CATECHISM 

OK 

rrxiCULTUUAL   CIL..MISTRY 


G  E  O  L  O  G 

UC-NRLF 


En'ihind,  and  \aUior 
I  Geulogy, ' 


AN   INTIJODI   "TION, 


JOHN    PITKIN    lOKTON, 

or  Fartniti^on,  Comieclicut. 


rUlM  Till:  13RJI1TI[  UNUI.ISH  ITDITION, 

Will.  N.Mi-s  and  AddUioils  by  llie  AuUior,  prcpai'ed  expressly  for 
this  Edition. 


ALBANY: 

KRASTUS    H.    PEASE. 

1 8  ■;  'i . 


£i 


THE  LIBRARY 

OF 

THE  UNIVERSITY 

OF  CALIFORNIA 

PRESENTED  BY 

PROF.  CHARLES  A.  KOFOID  AND 

MRS.  PRUDENCE  W.  KOFOID 


LIBRMt 


^^ 


RECOMMENDATIONS. 

From  Hon.  Saml.  Young,  Secretary  of  State  and  Super- 
iniendent  of  Common  Schools  of  the  State  of  New- 
York  ; 

I  have  carefully  examined  the  Catechism  of  Professor 
Johnston,  on  Agriculture.  It  is  the  only  scientific  work  on 
that  subject  I  have  ever  seen,  which  by  its  shortness  and 
simplicity  is  adapted  to  the  capacity  of  children  ;  and 
which,  on  being  illustrated  by  cheap  and  simple  experi- 
ments, as  he  recommends,  cannot  fail  to  make  a  lasting 
impression  on  the  juvenile  mind. 

It  gives  the  analysis  of  different  plants,  of  animals  and 
of  soils,  exhibiting  the  organic  and  inorganic  substances  of 
which  they  are  composed,  and  teaching  the  important 
truths  that  vegetables  drrive  a  part  of  their  nourishment 
from  the  air  and  the  remainder  from  the  earth  ;  that  diffe- 
rent vegetables  require  diflerent  kimis  of  food  and  in  va- 
riable quantities  ;  that  the  soil  may  be  destitute  of  nutri- 
tion for  one  kind  of  plant  and  not  for  another  ;  ami  the 
means  are  explained  of  supplying  to  an  exhausted  or 
meagre  soil  its  deficiencies.  It  also  gives  the  rationale  of 
the  dairy  and  the  fattening  of  animals. 

This  little  work  is  the  basis  of  both  agricultural  art  and 
science.  A  knowledge  of  its  principles  is  within  the  com- 
prehension of  every  child  of  twelve  years  old  ;  and  if  its 
truths  were  impressed  on  the  minds  of  the  young,  a  foun- 
dation would  be  laid  for  a  vast  improvement  in  that  most 
important  occupation  which  feeds  and  clothes  the  human 
race.  Instead  of  conjecture,  and  hazard,  and  doubt  and 
experiment,  as  heretofore,  a  knowledge  of  the  composition 
of  soils,  the  food  of  plants  and  the  processes  of  nature  in  the 
culture  and  growth  of  crops,  would  elevate  agriculture  to  a 
conspicuous  rank  among  the  exact  sciences. 

I  hope  that  parents  will  be  willing  to  introduce  this  brief 
catechism  into  the  Common  Schools  of  this  State. 

S.  YOUNG. 
Albany,  24th  January,  1845. 


Yale  College,  Laboratory,      ) 
^ew■Haven,  Ct.,  20th  Jany.  ISib.    S 

I  have  read  with  great  pleasure  and  profit  the  condensed 
little  Agricultural  Catechism  of  Prof.  James  F.  W.  John- 
ston  of  Scotland.  Like  every  production  of  his  pen,  it  is 
characterized  by  a  sound,  practical  good  sense,  vphich  adds 
double  value  to  his  scientific  labors,  rendering  them  availa- 
ble to  the  very  class  for  whom  they  are  more  es;  ccially  de- 
signed— practical  farmers. 

I  learned  with  pleasure  from  Prof.  Johnston,  that  Mr. 
John  P.  Norton  was  about  to  edit,  with  an  introduction,  his 
Agricultural  Catechism.  This  American  edition  should  be 
in  every  village  school  in  the  land ,  as  being  within  the  com- 
prehension of  all  intelligent  children  :  and  it  cannot  indeed 
be  too  highly  recommended  to  the  attention  of  all  classes  of 
teachers,  as  the  best  synopsis  yet  made  of  the  valuable  facts 
and  principles  which  have  been  established  in  the  important 
science  of  agriculture. 

B.  SILLIMAN,  Jr. 

I  consider  "J.  F.  W.  Johnston's  Catechism  of  Agricul- 
tural Chemistry  and  Geology,"  to  be  extremely  well  adapt- 
ed to  the  use  of  schools.,  and  that  it  ought  to  be  introduced 
as  a  text-book  into  all  our  rural  districts  where  farming  is 
the  principal  employment  of  the  population.  The  time  has 
come  when  Agriculture  is  to  be  taught  as  a  science  as  well 
as  cultivated  as  an  art,  and  a  little  book  like  this  sheds 
more  light  on  the  nature  of  soils,  the  elementary  principles 
of  plants,  and  the  food  necessary  for  their  growth  and  ma- 
turity, in  a  smallcompass,  tlianany  other  publicalion  I  have 
ever  seen.  The  youthful  mind  can  easily  be  made  to  com- 
prehend the  principles  it  teaches,  and  we  are  wanting  to  our 
own  and  the  great  interests  of  our  country,  if  at  this  time 
we  do  not  do  all  in  our  power  to  create  a  taste  and  diffuse  a 
knowledge  of  so  important  a  pursuit. 

J.  P.  BEEKMAN, 
late  Prest.  o/N.  Y.  S.  A.  Society. 

Kinderhook,  Jan.  22, 1845, 


Having  examined  Professor  Johnston's  Catechism  on 
Agricultural  Chemistry  and  Geology,!  most  cordially  unite 
in  the  recommendation  of  the  work.  Its  introduction  into 
our  Common  Schools,  will  form  a  new  era  in  the  education 
of  our  children.  The  time  has  arrived  in  which  every  pro- 
per effort  should  be  made  to  give  such  an  education  to  the 
rising  generation  as  will  prepare  them  rightly  to  appreciate, 
as  well  as  successfully  to  follow,  the  pursuits  of  agriculture, 
for  which  most  of  them  are  designed.  It  will  give  me  great 
pleasure  to  do  all  in  my  power  to  disseminate  this  little 
work,  which  I  doubt  not  will  produce  the  most  happy  effects 
throughout  our  country. 

BENJ,  P.  JOHNSON, 
President  N.  ¥.  State  J^ricultural  Society. 

Rome,  Jan.  23d,  1845. 


The  apparatus  necessary  to  perform  the  experiments 
mentioned  in  this  Catechism,  may  be  had  complete  of  Mr. 
George  Dexter,  Albany,  for  $3.50  ;  or  a  receiver  and  retort 
with  stand  for  from  $1.25  to  $2.00. 


CATECHISM 

OF 

AGRICULTUrvAL   CHEMISTRY 

AND 

GEOLOGY. 

BT 

JAMES  F.  W.  JOHNSTON,  M.A.,  FR.SS.L.&E. 

Honorary  Member  of  the  Royal  Agricultural  Society  of  England,  and  AuUlor 
of  "  Lectures  on  Agricultural  Chemistry  and  Geology." 

WITH 

AN  INTRODUCTION, 


JOHN   PITKIN   NORTON, 
Of  Farmington,  Connecticut. 

FROM  THE  EIGHTH  ENGLISH  EDITION, 

With  Notes  and  Additions  by  the  Author,  prepared  expressly  (or 
this  Edition. 


ALBANY: 

ERASTUS    H.    PEASE. 

1846. 


Edtered  according  to  Act  of  Coni^resg,  in  the  year  1845,  by 

ESASTUS    H.    PEA9E, 

ia  the  Clerk's  Office  of  the  Nor±em  District  of  New-Tork. 


INTKODUCTION 

TO    THE 

AMERICAN    EDITION. 


In  introducing  this  little  work  to  the  notice  of  the 
American  public,  I  am  encouraged  by  the  hope  that 
a  conviction  as  to  the  importance  of  the  new  know- 
ledge of  which  it  treats,  already  fixed  in  many 
minds,  will  soon  become  universal.  Agriculture, 
the  art  in  which  nine-tenths  of  the  capital  of  civil- 
ized nations  is  embarked,  upon  which  all  depend 
for  subsistence,  is  rising  towards  its  proper  rank  as 
a  science.  We  look  forward  to  the  time  when  it 
will  be  generally  conducted  upon  fixed  and  scienti- 
fic principles,  dependent  upon  immutabb  laws. 
Obstacles  may  retard,  but  cannot  permanentl)-  ar- 
rest its  progress,  and  those  who  receive  the  light 
that  we  now  possess,  and  keep  pace  with  our  in- 
creasing knowledge,  will  surelj'  reap  the  benefit 
which  always  results  from  the  application  of  en- 
lightened skill;  while  those  who  linger  behind 
must  be  content  to  grope  on  in  blind  uncertainty,  as 
our  forefathers  have  done. 


fca'i/j  onoo 


4  INTKODCCTION. 

I  am,  however,  aware  that  we  can  scarcely  expect 
the  present  generation  of  farmers,  engrossed  with 
the  cares  and  business  of  life,  with  their  prejudices 
and  habits  of  thought  strengthened  by  years,  gene- 
rally to  enter  this  new  field,  and  to  commence  with 
energy  the  study  of  what  seems  to  them  a  formida- 
ble science.  But  may  we  not  with  confidence  hope 
that  they  will  cheerfully  place  the  means  of  instruc- 
tion within  the  reach  of  their  children? 

Scientific  terms,  and  strict  modes  of  reasoning, 
are  already  becoming  common  in  the  daily  inter- 
course of  agriculturists.  In  the  next  generation 
this  will  become  almost  universal,  and  the  farmer 
who  now  neglects  the  instruction  of  his  children  in 
elementary  scientific  knowledge,  may  with  reason 
apprehend  that  more  skillful  and  better  taught  cul- 
tivators, will  hereafter  thrust  them  aside,  and  oc- 
cupy the  places  which  they  might  have  filled. 

That  children  may  be  early  and  thoroughly 
taught  this  elementary  science,  I  have  seen  most 
satisfactorily  proved.  At  the  late  show  of  the  High- 
land and  Agricultural  Society,  at  Glasgow,  five 
bo)-s  were  present  from  the  Lame  School  in  Ire- 
land. They  were  from  twelve  to  sixteen  years  of 
age,  and  were  sons  of  small  tenant  farmers.  In  the 
course  of  a  searching  public  examination,  they 
evinced  a  knowledge  of  elementary  chemistry,  as 


INTRODUCTION.  5 

applied  to  agriculture,  that  was  truly  surprising; 
and  not  only  were  they  conversant  with  this  branch 
of  chemistry,  but  with  practical  farming  also.  The 
expressions  of  delight  and  satisfaction  at  the  close 
of  the  examination,  were  unanimous.  These  boys 
are  taught,  it  must  be  noticed,  without  neglecting 
their  other  studies,  as  only  two  or  three  hours  a 
week  are  devoted  to  this  branch  of  instruction. 
When  their  course  of  study  is  complete,  they  are 
either  competent  to  take  charge  of  their  own  farms, 
or  to  act  as  land  stewards  or  agents  for  others. 

This  system  of  instruction  is  about  to  be  more  or 
less  perfectly  carried  out  in  three  thousand  of  the 
Irish  schools,  and  in  Scotland  a  great  change  is 
rapidly  taking  place.  The  schoolmasters,  at  their 
aunual  convention  a  few  weeks  since,  decided  unan- 
imously to  introduce  a  system  somewhat  resembling 
the  Irish,  into  all  the  Scottish  schools.  The  zeal, 
both  of  the  masters  and  the  people  of  Scotland,  is 
enthusiastic.  What  I  have  witnessed  of  it  in  va- 
rious parts  of  this  country,  has  made  me  desirous 
that  the  subject  should  be  brought  under  the  consi- 
deration of  my  own  countrymen. 

It  seems  to  me  that  our  circumstances,  at  least 
in  the  northeastern  and  northern  states,  are  pecu- 
liarly favorable.  We  have  in  almost  every  village 
an  academy,  or  a  school  higher  than  the  common 


6  INTRODUCTION. 

district  schools,  taught  generally  by  graduates  of 
our  colleges.  How  easy  for  these  teachers  to  de- 
vote two  hours  of  their  pupils'  time  in  each  week, 
to  the  study  of  such  a  work  as  this  Catechism  I  A 
few  shillings  will  supply  all  the  apparatus  necessa- 
ry for  the  simple  experiments  it  describes,  and  these 
experiments  will  indelibly  impress  upon  the  youth- 
ful mind,  the  nature  and  properties  of  carbon,  oxy- 
gen, nitrogen,  and  those  other  bodies  which  form 
our  plants,  our  food,  ourselves,  and  the  earth  upon 
which  we  live. 

The  district  schools,  also,  might  be  made  the 
means  of  conveying  similar  information.  Where 
the  community  is  interested,  the  teachers,  I  am  con- 
fident, will  be  found  ready  cheerfully  to  do  their 
part.  I  have  met  the  parish  and  other  schoolmas- 
ters in  various  parts  of  Scotland ;  they  vie  with 
each  other  in  their  desire  to  attain  and  impart  this 
new  knowledge.  My  own  fellow-citizens,  I  am 
sure,  will  not  be  less  eager  in  their  country's  ser- 
yice. 

An  attempt  to  recommend  this  Catechism  by  any 
praise  of  mine,  might  seem  presumptuous.  The 
wide  and  extensive  reputation  of  its  author — com- 
bining in  an  eminent  degree,  theoretical  with  prac- 
tical knowledge,  and  penetration  with  prudent  cau- 
tion, together  with  the  fact  that  this  little  work,  and 


INTKODTTCTION.  7 

his  Elements  of  Agricnltural  Chemistry  and  Geo- 
logy, are  the  text-books  in  all  the  Irish  as  well  as 
the  Scottish  schools,  will  be  a  sufficient  guarantee 
of  its  merit.  I  can  therefore  only  express  my  ear- 
nest desire  that  it  may  be  the  herald  of  agricultu- 
ral school  instruction  in  the  United  States.  I  trust 
that  it  may  be  attentively  perused  by  my  country- 
men generally,  old  as  well  as  young;  for  I  am  sa- 
tisfied that  many  will  feel  disposed,  after  reading 
it,  to  follow  the  example  of  an  Irish  gentleman, 
who  thanked  the  author  for  having  given  him  a 
•profession. 

The  present  edition  is  reprinted  from  the  eighth 
English  edition,  with  manuscript  alterations  and 
Additions  by  the  author. 

JOHN  PITKIN  NORTON, 

Farmington,  Conn. 

Edinburgh,  Nov.,  1S44. 


TO  THE  SCHOOLMASTERS  AND   TEACHERS  OF 
GREAT   BRITAIN  AND  IRELAND. 

Gentlemen, 

Having  written  the  present  little  work 
with  a  view  to  the  more  speedy  improvement  of  the  agri- 
culttire  of  our  common  country,  I  take  the  liberty  of  dedi- 
cating it  to  you.  No  class  of  men  possesses  in  so  high  a 
degree  the  power  of  promoting  an  object  so  important  to 
aU.  I  am  anxious,  therefore,  to  secure  not  only  your 
willing  support,  but,  if  possible,  your  cordial  co-operation 
also. 

The  land  from  which  our  crops  are  raised  must  be  ren- 
dered more  productive,  if  food  is  to  be  grown  at  home  for 
our  increasing  population.  But  the  produce  can  be  largely 
increased  only  by  the  application  of  increased  knowledge 
to  the  culture  of  the  soil; — and  it  is  the  rising  generation 
now  under  your  care,  which  must  possess  and  apply  this 
knowledge.  You  can  scarcely  render  a  higher  service  to 
your  country,  therefore,  than  by  imparting,  along  with 
your  other  instructions,  the  rudiments  of  that  kind  of  know- 
ledge on  which  its  prosperity  must  so  greatly  depend. 
Few  of  your  pupils  will  then  escape  from  your  hands  so 
early  as  not  to  have  already  learned  what  may  enable 
them  on  some  spot  or  other  in  after  life,  "  to  make  two 
blades  of  grass  to  grow  where  only  one  grew  before." 
I  have  the  honor  to  be. 
Gentlemen, 

Your  obedient  servant, 

JAMES  F.  W.  JOHNSTON. 

EoiNBtJKGH, 

1st  February,  1844. 


ADVERTISEMENT. 


The  Author  believes  that  the  country  teacher  who  may 
introduce  this  little  Catechism  into  his  school,  will  find  no 
difficulty  in  making  his  elder  classes  understand  the  differ- 
ent subjects  which  are  successively  adverted  to.  It  will 
not  be  necessary  to  make  them  commit  the  very  words  of 
each  answer  to  memory.  They  should  be  taught  rather 
to  make  themselves  masters  of  the  matter  of  each,  so  as 
to  be  able  to  express  the  sense  of  the  answers  in  words  of 
their  own. 

On  first  going  over  the  questions,  the  pupil's  attention 
may  be  confined  to  such  only  as  the  teacher  may  consider 
most  important  or  most  applicable  to  the  practice  of  the 
neighborhood  in  which  he  lives.  The  other  questions 
will  be  taken  up  on  a  second  perusal,  and  an  occasional 
general  catechising  upon  the  whole  book  will  fi.\  the  mat- 
ters treated  of  more  firmly  in  the  minds  of  his  scholars. 

The  teacher  himself  will  find  further  information  in  the 
Author's  Elements  and  pnhlished  Lectures  on  Agricultural 
Chemistry  and  Geology;  and  a  set  of  apparatus  especially 
prepared  for  this  Catechism,  may  be  obtained  from  Rich- 
ard GriiBn  &  Co.,  of  Glasgow,  at  a  cost  of  thirty  shillings. 


CATECHISM 

OK 

AGRICULTURAL  CHEMISTRY  AXD  GEOLOGY. 


Q.    What  is  agriculture'! 

A.  Agriculture  is  the  art  of  cultivating  the  soil. 
Q.    IF  hat  is  the  object  of  the  farmer  in  cultivating  the 
soil  ? 

A.  The  object  of  the  farmer  in  cultivating  the  soil  is, 
to  raise  the  largest  crops  at  the  smallest  cost,  and  with 
the  least  injury  to  the  land. 

Q.    What  ought  the  farmer  especially  to  know,  in  order 
that  he  may  attain  this  object  ? 

A.  The  farmer  ought  especially  to  know  ihe  nature  of 
the  crops  he  raises,  of  the  land  on  which  they  grow,  and 
of  the  manures  which  he  applies  to  the  land. 

I. —  OF  THE  NATURE    OF    THE    CROPS    HE    RAISES. 

Q.   Of  what  parts  do  all  vegetable  substances  consist  ? 

A.  All  vegetable  substances  consist  ol  two  parts,  one 
which  burns  away  in  the  fire,  called  the  organic  part, 
and  one  which  does  not  burn  away,  called  the  inorganic 
part. 

Here  Ihe  teacher  will  burn  a  bit  of  straw  or  wooil  in  the 
candle,  (fi^.  1,)  anil  show  that  one  part  burns  away,  and 
that  another  very  small  part — the  ash — doesnot  burn  away 


12 


CATECHISM    OF   AGRICULTtTRAL 


Q.  Which  of  these  livo  parts  is 
the  greater  in  quantity  ? 
A.  In  all  veg-etable  substances, 
the  organic  part  is  very  much  the 
greater.  It  forms  from  90  to  99 
out  of  every  100  lbs.  of  their 
weight. 

Q.  Of  what  elementary  bodies 
does  the  organic  part  of 
plants  consist  ? 
A.  The  organic  part  of  plants 
consists  of  four  elementary  bodies,  known  by  the  names 
of  carbon,  hydregen,  oxygen  and  nitrogen. 
Q.    What  is  carbon. 

A.  Carbon  is  a  solid  substance,  usually  of  black 
colour,  which  has  no  taste  or  smell,  and  burns  more  or  less 
readily  in  the  fire.  Wood-charcoal,  lamp-black,  coke, 
black-lead,  and  the  diamond,  are  varieties  of  carbon. 

The  teacher  will  here  exhibit  a  piece  of  charcoal  and 
show  how  it  burns  in  the  fire,  or  in  the  flame  of  a  can- 
iDe.  He  may  also  draw  their  attention  to  Uie  remarkable 
difference  in  appearance  between  cliarcoal  and  the  dia- 
mond, though  essentially  the  same. 

Q.    What  is  hydrogen  ? 

A.  Hydrogen  is  a  kind  of  air  or  gas  which  burns  in 
the  air  as  coal  gas  does,  but  in  which  a  candle  will  not 
burn,  nor  an  animal  live,  and  which,  after  being  mixed 
with  common  air,  explodes  when  it  is  brought  near  the 
flame  of  a  candle.  It  is  also  the  lightest  of  all  known 
stibstances 


CHEMISTRY   AND   GEOLOGV. 


13 


Here  the  teacher  will  take  a  beer  or 
champaign  glass,  (fig.  2,)  will  put 
into  it  some  pieces  of  zinc  or  iron 
filings,  and  pour  over  them  a  small 
quantity  of  oil  of  vitriol  (sulphuric 
acid)  diluted  with  twice  ils  bulk 
of  water,  and  cover  the  glass  for  a 
few    minutes.     On    putting    in   a 
lighted   taper,  an  explosion   will 
take  place.     He  will  then  repeat 
the    same  experiment  in  a  phial, 
into  the  cork  of  which  he  has  introduced  a  common  gas 
jef,  (Bg.  3.)     After  a  short  time,  when  the  hydrogen  gas 
produced  has  driven  out  all  the  common  air  fi-om  the  bot- 
Fig.  3.  tie,  a  light  may  be  applied  to  the 

jet,  when  the  gas  will  take  fire  and 
burn.     The  cork  and  jet  may  now 
be   taken  out  of  the   bottle,  and  a 
lighted    taper    introduced    into    it, 
when  the  taper  will  be  extjngushed, 
while   the  gas  itself  will    take    fire 
and  burn  at  the  mouth  of  the  bottle. 
Lastly,   if  the   teacher   possesses  a 
small    balloon,  he    may  fill  it  with 
the  gas  by  attaching  it  to  the  mouth 
'  the  bottle,  and   may  thus  show    that 
the  gas  is  so  light  that  it  will  carry  heavy  bodies  up  with 
it  through  the  air. 
Q.    tVhat  is  oxygen  ? 

A.  Oxygen  is  also  a  kind  of  air  in  which  a  candle 
bitrns  with  great  brilliancy,  in  which  animals  also  can 
live,  and  which  is  lieavier  than  hydrogen  or  common  air. 
It  forms  one-fifth  of  (he  bulk  of  the  air  we  breathe. 


14 


CATECHISM    OF   AGRICTTLTURAL 


The  teacher  will  here  exhibit  a  bottle 
of  oxygen  gas,    (fig.  4,)    ami  show 
how  rapidly  and  brillianlly  a  lighted 
taper  burns  when  introiluccd  into  it. 
The  least  troublesome  mode  of  prepar- 
ing oxygen  gas,   is  lo  heat  red  oxide 
of    mercury    in    a    small    retort    by 
means  of  a  spirit  lamp,  and  lo  col- 
lect the  metallic  mercury  as  it  dis- 
tils over  and  trickles  down  the  beak 
of  the  retort      This  is  not  so    very 
a  costly  process  as  it  appears  to  be, 
since  there  is  no  loss  of  anything.     A 
pound  of  red  oxide  costs  6s.  Sd.,  and 
gives   14  oz.  of   metallic   mercury, 
worth  4s.  8d. 
Oxygen  gas  may  also  be  prepared  by  mixing  sulphuric  acid 
(oil  of  vitriol,)  with  black  oxide  of  manganese,  in  fine  pow- 
der in  a  retort,  and  applying  the  heat  oT  a  lamp ;  or  by  rub- 
bing together  in  a  mortar  e  |ual  weights  of  oxide  of  copper 
and  chlorate  of  potash,  putting  the  mixture  into  a  small  re- 
tort,   and  applying  the  lamp  as  before.      The  last  is  the 
quickest  method  of  the  three. 
Fig    5 

*  The   properties   of  oxygen   may  be 

very  well  shown  without  the  neces- 
sity of  collecting  the  gas.  Thus, 
the  mixture  of  chlorate  of  potash 
and  oxide  of  copper  above  descri- 
beil,  may  be  put  into  an  open  tube, 
(flg.  5.)  and  the  flame  of  a  lamp 
applied  for  a  few  minutes;  when  a 
bit  of  red  hot  charcoal,  or  a  match 
of  which  a  spark  is  still  red  at  the 
extremity,  will  burn  brilliantly  if  introduced  at  a. 


CHEMISTRY    AND    GEOLOGY. 


15 


*'g-  ".  Or  the  mixluie  may  be  put  into  a  com- 

mon open  flasU,  (tig.  6,)  anil  heat  ap- 
plied, when  a  taper,  or  phosphorus,  or 
charcoal,  or  sulphur,  may  be  inlrmluc- 
etl  at  the  emi  of  a  wire,  and  will  burn 
brilliantly. 

Q.    IVhat  is  nitrogen  ? 

A.  Nitrogen  is  also  a  kind   of  air 

differing  from   both   the   other    two. 

Like  hydrogen,  a  taper  will  not  burn 

nor  will  an  aninnal  live  in  it,  but  ui>- 

like  hydrogen,  it  will  itself  not  burn, 

and  therefore  does  not  take  fire  when  hronght  near  ihe 

flame  of  a  candle.     It  is  alillle  lighter  Ihan  atmospheric 

air,  of  which  it  forms  four-fifths  of  the  bulk. 

Fig.  7. 

The  teacher  will  here  exhibit  a 

bottle  of  this  gas,  and  show 
that  a  lighted  taper  is  extin- 
guished when  introducei-l  into 
it. 
The  easiest  mode  of  preparing 
nitrogen,  is  by  mixing  togeth- 
er a  quantity  of  sal  ammoniac 
with  half  ils  weight  of  salt- 
petre, both  in  tine  powder, 
and  heating  them  in  a  retort 
ovf  r  a  lamp.  The  gas  which  comes  off  is  collected  over 
water,  as  shown  on  the  following  page,   (fig.  8.) 


16  CATECHISM    OF    AGEICTJLTUKAL 

Fig.  8. 


Q.  Do  all  vegetable  substances  contain  these  four  ele- 
mentary bodies  ? 
A.  No,  the  greater  number  contain  only  three,  viz: 
carbon,  hydrogen,  and  oxygen. 

Q.  Name  some  of  the  more  common   substances   which 
contain  only  these  three  ? 
A.  Starch,  gum,  sugar,  the  fibre  of  wood,  oils,  and 
fats,  contain  only  these  three  elements. 
Q.   Of  what  substances  does  the  inorganic  part  of  the 
plant  consist  ? 
A.  The  inorganic  part  of  plants  contains  from  eight 
to  ten  ditferent  substances,  namely :  potash,  soda,  lime, 
magnesia,  oxide  of  iron,  oxide  of  manganese,  silica, 
chlorine,  sulphuric  acid,  or  oil  of  vitriol,  and  phospho- 
ric acid. 

Here  the  teacher  may  exhibit  to  his  pupils,  potash  in  the 
form  oCthe  common  pearl  ash  of  the  shops;  soila,  in  that 
of  the  common  soda  of  the  shops;  lime  and  magnesia,  in 


CHEMISTRY   AND    GEOLOGY.  17 

the  lotmsol quicklime  and  calcined  magnesia;  oxide  of  iron, 
in  the  form  of  rust  of  iron;  silica,  in  the  form  of  a  piece 
of  Jlint,  rock  crystal  or  quartz,  (chucky  stone;)  abottle  of 
chlorine  gas,  one  of  sulphuric  acid,  (oil  of  vitriol,)  and 
one  containing  a  little  phosphoric  acid,  or  burnt  bones 
in  which  phosphoric  acid  is  present.  By  placing  the86 
substances  before  the  eyes  of  (he  pupils  occasionally, 
and  allowing  them  to  determine  and  taste  them,  they 
will  soon  become  familiar  with  their  names,  and  with 
their  several  qualities. 

Q.    What  is  potash  ? 

A.  The  common  potash  of  the  sliops  is  a  white  pow- 
der, which  has  a  peculiar  taste  called  an  alcaline  taste, 
and  which  becomes  moist,  and  at  last  runs  to  a  liquid 
when  exposed  for  a  length  of  time  to  the  air.  It  is  ob- 
tained by  washing  wood  ashes  (the  ashes  left  by  wood 
when  it  is  burned,)  with  water,  and  afterwards  boiling 
the  liquid  to  dryness. 

The  teacher  will  here  allow  his  pupils  to  taste  the  potash, 
that  they  may  become  familiar  with  the  meaning  of  the 
word  alcaline  as  applied  to  (aste.     (See  p.  20.) 
Q.    What  is  soda  ? 

A.  The  common  soda  of  the  shops  is  a  glassy  or  crys- 
tallized substance,  which  has  also  an  alcaline  taste,  but 
which,  unlike  potash,  becomes  dry  and  powdery  by  being 
exposed  to  the  air.     It  is  manufactured  from  sea  salt. 
The  teacher  will  show  a  crystal  of  the  common  soda  of  the 
shops,  and  explain  the  meaning  of  the  word  crystallized- 
Q.    What  is  lime? 
A .  Lime  or  gMicfe-lime  is  a  white  earthy  substance 
2 


18  CATECHISM   OF   AGRICULTURAL 

wliich  is  obtained  by  burning  common  limestone  in  Ihe 
lime-kiln.  It  has  a  slightly  burning  taste,  and  becomes 
hot  and  slakes  when  water  is  poured  upon  it. 

The  teacher  will  exhibit  a  piece  of  quicldimc,  will  allow 
his  pupils  to  tasle  it,  and  will  pour  water  upon  it,  that  it 
may  fall  to  powiler.     They  will  thus  become  familistr 
with  the  word  slake. 
Q.    IVhat  is  magnesia  ? 

A.  Magnesia  is  the  white  powder  sold  in  the  shops 
under  the  name  of  calcined  mai;nesia.     It  has  scarcely 
any  taste,  and  is  extracted  from  sea  water  and  from  some 
kinds  of  limestone  rock  called  Magnesian  limestones. 
Q.    H'hal  is  iron  7 

A.  Iron  is  a  hard  bluish  gray  metal,  which  is  manu- 
factured in  large  quantities  incur  iron- works,  and  is  used 
for  a  great  variety  of  useful  purposes. 

The  teacher  will  here  explain  the  word  metat,  by  show- 
ing that  such  common  metals  as  iron,  copper,  leail,  sil- 
ver and  goUl,  have  a  lustre,  weight,  anil  malleability  not 
possessed  by  wood,  stones,  and  other  substances  to  which 
the  name  of  metals  is  not  applied. 
Q.    ffhnt  is  oxide  of  iron  ? 

A.  When  polished  iron  is  exposed  to  the  air  it  gradu- 
ally becomes  covered  with  rust.  This  rust  consists  of 
tbe  metal  iron,  and  of  the  gas  oxygen  which  the  iron  has 
attracted  from  the  air,  and  hence  it  is  called  an  oxide 
of  iron. 

The  teacher  will  explain  more  fully,  that,  when  metals 
combine  with  oxygen,  they  form  new  substances,  to 
Which  the  name  of  oxides  is  given,  and  illustrate  this  by 


CHEMISTRY    AND    GEOLOGY.  19 

a  reference  to  the  red  oxide  of  mercury,  which,  by  the 
heat  of  the  lamp  he  had  resolved  or  decomposed  into  oxy 
gen  gas  and  metallic  mercury.      (Sec.  fig.  8.) 
Q.    What  is  oxide  of  manganese  ? 

A.  Oxide  of  manganese  is  a  substance  very  much  like 
oxide  of  iron,  which  occurs  in  soils  and  plants,  usually 
in  very  small  quantity. 
Q.    fVhat  is  silica  ? 

A.  Silica  is  the  name  given  by  chemists  to  the  sub 
stance  of  flint,  of  rock-crystal,  and  of  sandstones. 
Q.    What  is  chlorine  7 

A.  Clilorine  is  a  kind  of  air  which  has  a  greenish-yel- 
low colour,  and  a  strong  suffocating  smell.  ♦  A  taper 
burns  in  it  with  a  dull  smoky  flame.  It  exists  in  com 
mon  salt  in  large  quantity. 

The  teacher  will  exhibit  a  bottle  of  this  gas,  and  may  ad- 
vert to  the  remarkable  fact  that  this  very  noxious  gas 
should  form  more  than  half  the  weight  of  the  very 
wholesome  substance  common  salt,  100  lbs.  of  common 
salt  containing  60  lbs.  of  chlorine.  This  gas  is  readily 
prepared  by  pouring  muriatic  acid  on  black  oxide  of 
manganese  in  a  retort^  and  applying  a  gentle  heat.  It 
should  be  collected  over  hoi  water. 
An  easier  mode  of  showing  some  of  the  properties  of  thia 
gas,  is  to  put  a  little  dry  chloride  of  lime  into  the  bottom 
of  a  tall  glass,  (fig.  2,)  anil  pour  upon  it  strong  sulphuric 
aciil.  Chlorine  gas  will  be  given  off,  and  will  gradually  fill 
the  lower  part  of  the  glass,  and  the  boys  may  then  be  made 
to  smell  it,  and  it  maybe  shown,  1st.  That  a  taper  burns 
in  it  with  a  smoky  flame  and  is  soon  extinguished. 

*  U  is  two  and  a  half  tiinea  heavier  than 


20  CATECHISM    OF   AGRICULTURAL 

2d.  That  it  is  much  heavier  than  common  air,  by  pour- 
j  ing  it  from  one  glass  to  another,  or  upon  the  flame  of  a 
candle,  (figs.  10  and  11.)  3d.  That  phosphorus  takes 
fire  in  it  of  its  own  accord.  4th.  That  it  gives  a  red 
color  to  a  solution  of  iodide  of  potassium  when  poured 
upon  its  surface,  or  a  purple  color  if  a  little  dissolved 
starch  be  previously  mixed  with  the  solution  of  the 
iodide.  5lh.  That  the  color  of  red  cabbage  is  discharg- 
ed by  it,  (see  under  sulphuric  acid.)  It  is  not  absolutely 
necessary  for  the  teacher  to  make  all  these  experiments, 
but  they  are  very  simple,  and  they  are  likely  so  to  im- 
press the  knowledge  of  this  gas,  chlorine,  upon  tiie  mind 
of  the  pupil,  that  he  will  never  forget  it. 

Q.    fVhat  is  sulphuric  iicii  or  oil  of  vitriol  I 

A.  Sulphuric  acid  or  oil  of  vitriol  is  a  very  sour  burn- 
ing, oily  liquid,  which  is  manufactured  from  burning 
sulphur,  (brimstone.)  It  exists  in  common  gypsum,  in 
alum,  and  in  Glauber  and  Epsom  salts. 

The  teacher  will  here  exhibit  oil  of  vitriol,  and  show  that 
when  a  piece  of  straw  is  put  into  it,  it  is  charreil  or  burn- 
ed black.  He  will  also  exhibit  gypsum,  alum,  Glauber 
and  Epsom  salts,  and  show  tliat,  though  the  sulplimic 
acid  exists  in  them,  they  have  none  of  its  burning  pro- 
perties. He  will  also  explain  the  meaning  of  the  term 
acid  or  sour.  Besides  being  more  or  less  sour  to  the 
taste,  he  may  show  that  acid  substances  redden  vegetable 
colors — such  as  decoction  of  red  cabbage  or  of  violets, 
or  of  the  substance  he  will  buy  in  the  shops  by  the  name 
of  litmus;  and  that  alcaline  substances,  or  alcali,  such  as 
hartshorn,  common  soda,  pearl  ash,  or  quick  lime,  re- 
store the  blue  color. 


//^"^"""^^^^^ 


CHEMISTRY   AND    GEOLOGY.  21 

Q.    What  is  phosphoric  acid  ? 

A.  Phosphoric  acid  is  also  a  very  sour  substance, 
which  is  formed  by  burning  phosphorus  in  the  air.  It 
exists  in  Urge  quantity  in  the  bones  of  animals. 

If  the  teacher  possess  any  phospho- 
rus, he  may  here  show  how  i(  burns 
with  u-hite  fumes  in  the  air,  and 
may  collect  these  white  fumes — 
which    are    phosphoric    acid — by 
holding    over    them  a    cold  glass 
or  metal  jilatc,  or   he    may  sim- 
ply burn  the  phosphorus  in  a  little  clip  under  a  tumbler, 
(fig.  9.) 
A  still  simpler  way  of  making  his  pupils  acquainted  with 
phosphorus  and  phosphoric  acid,   is  to  take  a  common 
lucifer  match,  of  the  variety  that  kindles  without  explo- 
sion, and  to  rub  the  end  of  it  on  the  sand-paper  so  gently 
as  not  to  kindle  it.     If  it  be  now  brought  near  the  nose 
the   smell  of  phosphorus    will  be  perceived.     If  it  be 
again  rubbed  so  as  to  lake  fire,  it  will  burn  with  a  white 
flame,   and  will  for  a  short  time  give  a  white  smoke. 
Thin  while  smoke  is  phosphoric  acid.     It  is  a  curious  fact, 
that  about  200,000  lbs.  of  phosphorus  are  used  In  Lon- 
don every  year  for  the  manufacture  of  Lucifer  matches 
alone. 
Q.  jirc  all  these  substances  to  be  found  in  the  inorganic 
part  of  plants  ? 
A.  Yes,  they  are  to  be  found  in  the  ash  of  all  our  usu- 
ally cultivated  plants. 

Q.  Do  all  plants  leave  the  same  quantity  of  ash  when 
burned ? 
A.  Xo      Some   leave   much  more   ash   than  others 


22  CATECHISII    OF    AGRICULTURAL 

Thus   100  lbs.  of  hay  may  leave  9  or  10  pounds  of  ash, 
while  100  lbs.  of  wheat  leave  less  than  2  lbs.  of  ash. 
Q.  Does  the  mh  of  different  plants  contain   all  these 
substances  in  the  same  proportion  ? 

A.  No.  They  exist  in  different  proportions  in  the  ash 
of  different  plants — the  .ish  of  wheat,  for  example,  con 
tains  more  phosphoric  acid  than  that  of  hay,  while  tha* 
of  hay  contains  more  lime  than  the  ash  of  wheat. 

Compare  Tables  I.  and  III.  pages  38  and  43. 

II. OF     THE    ORGANIC     FOOD    OF    PLAXTS. 

Q.  Do  plants  require  food  as  animals  dot 

A.  Yes,  all  plants  require  constant  supplies  of  food  iii 
order  that  they  may  live  and  grow. 
Q.    Where  do  plants  obtain  their  food  1 

A.  They  obtain  it  partly  from  the  air  and  partly  from 
the  soil. 
Q.  How  do  they  take  in  their  food  ? 

A.  They  take  it  in  by  their  leaves  from  the  air,  and 
by  their  roots  from  the  soil. 
Q.  Do  plants  require  two  distinct  kinds  of  foodi 

A.  Yes,  they  require  organic  food  to  support  their  or- 
ganic pjrt,  and  inorganic  food  to  support  their  inorganic 
part. 
Q.    Whence  do  they  obtain  their  organic  food  ? 

A.  They  obtain  their  organic  food  partly  from  the 
air  and  partly  from  the  soil. 
Q.    Whence  do  they  obtain  their  inorganic  food? 

A.  They  obtain  their  inorganic  food  wholly  from  the 
soil  in  which  they  grow. 


CHEMISTRY    AND    GEOLOGY. 


23 


Q.  In  what  form  do  plants  take  in  organic  food  from 
the  air  ? 
A-  In  the  form  chiefly  of  carbonic  acid  gas. 
Fig.  10.         Q.    fVhat  is  carbonic  acid  gas  1 

A.  It  is  a  kind  of  air  which  has  no 
colour,  but  has  a  peculiar  smell.  Burn- 
ing bodies  are  extinguislied  in  it,  and 
animals  die,  and  it  is  heavier  than  com 
mon  air.  It  causes  the  boiling  up  of  so- 
da water,  and  tlie  frothing  of  beer,  and 
forms  nearly  half  the  weight  of  all  lime- 
stone rocks. 

Here  the  teacher  will  prepare  carbonic 
aciJ  gas,  by  pouring   dilute    muriatic 
acid,  (spirit  of  salt,)  upon  bits  of  lime- 
stone, or  of  the  common  soila  of  the  shops,  in  a  tall  co- 
vered beer  glass,  (as  in  fig.  2.)     He  will  show  that  a 
burning  taper  is  ex- 
tinguished   by    this 
gas;  but  that  it  tioes 
not,  like  hyilrogen, 
lake    fire    itself;  — 
that  it    is  so  heavy 
that  it  may  be  pour- 
ed from  one  glass  to 
anoiher,    (fig.    10;) 
anil  that  when  pour- 
ed from  a  large  tum- 
bler a  common  can- 
dle may  be  put  out 
by  it,  (fig.  ]].) 


Fig.  n. 


24  CATECHISM    OF   AGRICULTURAL 

Q.  Does  carbonic  acid  gas  form  a  large  part  of  the  at' 
mospheric  air  ? 

A.  No,  Ihe  atmospheric  air  consists  almost  entirely 
of  a  mixture  of  oxygen  and  nitrogen  gases.  Five  gai 
Ions  of  air  contain  about  four  of  nitrogen  and  one  of 
oxygen,  but  in  5000  gallons  there  are  oiJy  2  gallons  ol 
carbonic  acid  gas. 
Q.  Do  plants  drink  in  much  carbonic  acid  from  the  air  ? 

A.  Yes,  they  drink  in  a  very  large  quantity. 
Q.  I/ou'  can  plants  drink  in  so  large  a  quantity  of  this 
gas  from  the  air,  which  contaiiis  so  little'! 

A.  They  spread  out  their  broad  thin  leaves  in  great 
numbers  through  the  air,  and  thus  are  able  to  suck  in  the 
carbonic  acid  from  a  large  quantity  of  air  at  the  same 
time. 
Q.  How  do  they  suck  it  in  ? 

A.  By  means  of  a  great  number  of  very  small  open- 
ings or  mouths  which  arespreadcvery  where,  especially 
over  the  under  surface  of  the  leaf. 
Q.   Do  the  leaves  suck  in  this  carbonic  acid  at  all  times  ? 

A.  No,   only  during  the  day  time.     During  the  night 
they  give  olf  a  quantity  of  carbonic  acid. 
Q.    IFhat  does  carbonic  acid  consist  off 

A.  Carbonic  acid  consists  of  carbon,  or  charcoal,  and 
oxygen. 

6  lbs.  of  carbon  and  16  lbs.  of  oxygen  form  22  lbs.  of  car- 
bonic aciil. 
Q.  Hoiv  do  you  prove  this  ? 

A.  By  burning  charcoal  in  oxygen  gas,  when  carbon- 
ic acid  gas  will  be  formed. 


CHEMISTRY    AND    GEOLOGY. 


25 


The  leacher  will  show  this  experiment  by  intioilucing  a 
piece  of  red  hot  charcoal  into  a  bottle  of  oxygen  gas  un- 
til the  charcoal  is  extinguished,  when,  upon  putting  a 
lighted  taper  into  the  bottle,  he  will  find  carbonic  acid 
has  been  formed,  for  the  taper  will  be  extinguished. 
Q.  Does  the  plant  retain  both  the  carbon  and  the  oxygen 
contained  in  the  carbonic  acid  that  is  absorbed  by 
its  leaves  ? 
A.  No,  it  retains  only  the  carbon,  giving  off  the  oxy- 
gen again  into  the  air. 

Q.  How  do  you  show  that  the  leaves  give  off  this  oxygen 
gasl 
A.  By  putting  a  few  green  leaves  under  a  tumbler  or 
Fig.  12.  gas-receiver  full  of  water, 

and  selling  lliem  out  in  the 
.sunshine,  when  small  bub- 
bles of  oxygen  gas  will  be 
seen  to  rise  from  the  leaves, 
and  to  collect  in  the  upper 
part  of  the  tumbler  (fig.  12.) 
Q.  Do  the  leaves  of  plants 
drink  in  any  thing  elst 
from  the  atmosphere  ? 
A.  Yes,  they  drink  in  watery  vapour. 
Q.    What  purpose  does  this  vapour  serve  ? 

A.  It  serves  in  part  to  moisten  the  leaves  and  stems, 
and  partly  to  form  the  substance  of  the  jdant  itself. 
Q.  In  what  form  do  plants   take  in  carbon  from  the 
soil  ? 
A.  In  the  form  of  carbonic  acid,  humic  acid,  and 


26  CATECHISM    OF    AGRICULTURAL 

some  other  substances  which  exist  in  the  black  vegeta 

ble  matter  of  tlie  soil. 

If  the  teacher  wishes  to  form  humic  acid,  he  has  only  to 
dissolve  a  little  common  soila  in  water,  boil  the  solution 
upon  finely  powilereil  peat  or  rich  dark  soil,  pour  off 
the  solution  when  it  has  stooil  to  settle,  and  add  weak 
spirit  of  salt  to  it.  Brown  flocks  will  fall,  which  are 
humic  acid.  This  huniic  acid  consists  of  carbon  and 
water  only — see  the  table  on  page  twenty-eight. 

Q.  /'I  what  forms  do  plants  derive  nitrogen  from  the 
soil? 
A.  In  the  forms  of  ammonia  and  nitric  acid. 
The  properties  of  these  two  substances  are  described  in 
Section  VI.,   where  they  are  treated  of   in  connection 
with  certain  manures  in  which  they  exist. 

III. —  OF    THE    SUBSTANCE    OF    PLANTS. 

Q.    What  does  the  substance  of  plants  chiefly  consist  of  7 

A.  The  substance  of^Knts  chiefly  consists  of  woody 
fibre,  starch,  and  gluten. 
Q.    What  is  woody  fibre  1 

A.  Woody   fibre   is   the   substance  which  forms  the 
greater  part  of  all  kinds  of  wood,  straw,  hay,  and  chaff, 
of  the  shells  of  nuts,  and  of  cotton,  flax,  hemp,  &c. 
Q.    What  is  starch  ? 

A.  Starch  is  a  white  powder,  which  forms  nearly  the 
whole  substance  of  the  potatoe,  and  about  halfthe  weight 
of  oat-meal,  wheaten  flour,  and  of  the  flour  of  other 
kinds  of  grain  cultivated  for  food. 
Q.    What  in  gluten  ? 

A.  Gluten  is  a  substance  like  bird-Iirae,  which  exists. 


CHEMISTRy    AND    GEOLOGY. 


27 


along  with  starch,  in  ahnost  all  plants.  It  may  be  ob- 
tained from  wliealen  flour,  by  making  it  into  a  dough, 
and  washing  it  with  water,  (fig.  13.) 

Fig.   13.  The  teacher  will  here  mix 

flour  with  water  into  a 
dough,  and  wash  it  with 
water  upon  a  piece  of 
thin  muslin  tied  over  the 
mouth  of  a  tumbler  or 
lar^e  glass,  and  will  show 
how  the  milky  wa'er  car- 
ries the  starch  through  the 
muslin,  and  leaves  the 
gluten  beliind,  and  how, 
after  a  time,  the  slarch 
settles  at  the  bottcim  of  the 
water,  in  the  form  of  a 
white  pow^ler. 

Q.    Which   of  these    three  substances   is    usually  moat 
abundant  in  plants  ? 
A.  The  woody  fibre  is  the  most  abundant  in  the  stems 
of  plant?)  and  the  starch  in  their  seeds. 
Q.  Is  starch  found  in  the  roots  of  plants  ? 

A.  Yes,  it  exists  abundantly  in  the  potatoe  and  other 
similar  roots. 

Q.    What  do  woody  fibre  and  starch,  and  also  gum  and 
sugar  consist  of! 
A.  They  all  con-ist  of  carbon  and  water  only. 
The  teacher  may  suspend  on  the  walls  of  his  school-room 

the  followmg  table: 
36  lbs.    of  carbon  and  36  lbs.  of  water  form  72  lbs.  of 
woody  fibre. 


88  CATECHISM    OF    AGRICULTURAL 

36  lbs.  of  carbon  and  45  lbs.  of  water  form  81  lbs.  of  dry 

starch  or  gum. 
36  lbs.  of  carbon  and  49^  lbs.  of  water  form  85i  lbs.  of 
loaf-sugar  or  sugar-candy;  and  36  lbs.  of  carbon  and  27 
lbs.  of  water  form  63  lbs.  of  humic  acjd. 
Q.  Mo-y  these  substances  then  be  formed  from  the  kinds 
of  food  which  the  leaves  drink  in  from  the  air  ? 
A.  Yes,  because  the  leaves  drink  in  carbonic  acid  and 
water. 

Q.   Can  you  tell,  then,  why  the  leaves  give  off  the  oxygen 
of  the  carbonic  acid  into  the  air! 
A.  Yes,  they  require  only  carbon  and  water  to  form 
the  woody  fibre  and  starch,  of  which  they  consist,  and 
therefore  they  give  ofi'the  oxygen  of  the  carbonic  acid 
because  they  cannot  make  use  of  it. 
Q.  If  plants  suck  in  so  much  carbonic  odd  from  the 
air,  may  they  not  at  length  rob  the  air  of  the  whole 
of  the  carbonic  acid  it  contains  ? 
A.  No,  because  new  supplies  of  tliis  gas  are  continu- 
ally returning  into  the  air. 
Q.    Whence  do  those  supplies  come  ! 

A.  They  come  from  three  sources ;  first,  from  the 
breathing  of  animals,  since  all  animals  throw  off  a  small 
quantity  of  carbonic  acid  from  their  lungs  every  time 
they  breathe. 

Second,  from  the  burning  of  wood,  coal,  candles,  &c., 
since  the  carbon  which  wood  contains,  when  it  burns  in 
the  air,  forms  carbonic  acid  gas  just  as  carbon  when 
burned  in  oxygen  does. 

Third,  from  the  decay  of  vegetables  and  roots  in  the 
soil,  since  this  decay  is  only  a  slow  kmd  of  burning,  by 


CHEMISTRY    AND    GEOLOGY.  29 

which  the  carbon  of  plants  becomes  converted  into  car- 
bonic acid. 

Q.  Do  animals  and  plants  thus  appear  to  live  for  each 
other's  support  ? 
A.  Yes,  the  animal  produces  carbonic  acid,  upon 
which  plants  live,  and  from  this  carbonic  acid  and  water 
together,  plants  produce  starch,  &c.,  upon  which  animals 
'ive. 

Q.    Woody  fibre,  starch,  gum,  and  sugar  consist  of  car- 
bon and  toater  only;  of  what  does  water  itself  con- 
sist ? 
A.   Water  consists  of  oxygen  and  hydrogen. 
Q.  How  much  of  each  of  these  elements  is  contained  in 
water  ? 
A.  Every  9  lbs.  of  water  contain  about  8  lbs.  of  oxy- 
gen, and  1  lb.  of  hydrogen. 

Q.  Is  it  not  a  very  extraordinary  thing  that  liquid  ica- 
ter,  which  puts  out  all  fire,  should  consist  oj  two 
gases,   one   of  which   (^hydrogen,)    burns  readily, 
while  in  the  other  (^oxygen,')  bodies  burn  with  great 
brilliancy  ? 
A.  Yes,  it  is  very  wonderful;  but  there  are  many  oth- 
er substances  the  composition  of  which  is  almost  equally 
extraordinary. 
Q.   Can  you  name  any  such  substances  ? 

A.   Yes,  it  is  almost  equally  extraordinary  that  white 
starch  should  consist  of  black  charcoal  and  water  only, 
— and  that  sugar  and  gum  should  consist  of  the  same 
elements  as  starch  and  woody  fibre. 
Q.   Of  what  elements,  i/ien,  do  all  these  substances  con- 


30  CATECHISM    OF    AGRIC0LTUEAL 

A.  They  all  consist  of  carbon,  hydrogen  and  oxygen. 

The  teacher  may  lake  this  opportunity  of  explaining  more 
particularly  the  woril  elements,  contrasting  the  nature  of 
the  elementary  boities,  hydrogen,  oxygen,  carbon,  and 
nitrogen,  tvhich  cannot  be  separated  or  split  up  into  mort 
than  one  kind  of  viatter,  with  such  compound  bodies  as 
carbonic  acid,  water,  starch,  and  oxide  of  mercury, 
which  can  be  separated  into  more  than  one. 

Q.   Of  what  does  gluten  cmisist  ? 

A.  Gluten  consists  of  all  the  four  elements— carbon, 
hydroa^en,  oxygen,  and  nitrogen — ^united  together. 
Q    Does  the  plant  derive  from  the  air  all  the  elements 
of  which  gluten  consist  si 

A.  No,  it  may  obtain  carbon,  hydrogen,  and  oxygen, 
as  we  have  seen,  from  the  air,  but  the  nitrogen  it  obtains 
almost  solely  from  the  soil. 


IV.^OF    THE    SOIL.    ON    WHICH    PLANTS    GKOW. 

Q.    TVhat  does  the  soil  consist  of! 

A.  The  soil  consists  of  an  organic  or  combustible, 
and  of  an  inorganic  or  incombustible  pait. 
Q.  How  do  you  show  this  ? 

A.  By  heating  a  portion  of  soil  to  redness  on  a  bit  of 
sheet  iron,  or  on  the  end  of  a  knife,  either  in  Ihe  fire  or 
over  a  lamp.  The  soil  will  first  turn  black,  showing  the 
presence  of  carbonaceous  matter,  and  will  afterwards  as- 
sume A  grey  brown  or  reddish  color  as  this  black  orga- 
nic matter  burns  away. 


CHEMISTRY    AND    GEOLOGY.  3l 

Fig.  14.  The  teacher  will  show 

this     experiment, 
anil   will    explain 
(he    meaning     of 
the  new  wonlcor 
bonace&us^ 
Q     Whence  is  tha 
organic  part    of 
the  soil  derivedi 
A.  It  is  derived  from  the  roots  and  stems  of  decayed 
plants,  and  from  the  dung  and  resnains  of  animals  and 
insects  of  various  kinds. 

Q.  Does  this  organic  part  form  a  large  proportion  of 
the  soil  ? 
A.  Of  peaty  soils  it  forms  sometimes  three-fourths  of 
the  whole  weight;  but  of  rich  and  fertile  soils  it  does 
not  usually  form  more  than  from  a  twentieth  to  a  tenth 
of  the  whole  weight. 

Q.   Can  a  soil  bear  good  crops  which  does  not  contain 
a  considerable  proportion  of  organic  matter? 
A.   Not  in  our  climate.     A  rich  soil  generally  con- 
tains at  least  one-twentieth  of  its  weight  (5  percent.)  of 
organic  matter. 

Q.  Does  the  organic  matter  increase  or  diminish  in  tht 
soil,  according  to  the  way  in  which  it  is  cultivated  f 
A.  Yes,  it  diminishes  when  the  land  is  frequently 
ploughed  and  cropped,  or  badly  manured  ;  and  it  in- 
creases when  the  land  is  planted,  when  it  i.-s  laid  down  to 
permanent  pasture,  or  when  large  doses  of  farm-yard 
manure  or  of  peat  compost  are  given  to  it. 


32  CATECHISM    OF    AGKICXTLTUEAL 

Q.    fVhat  purpose  does  this  organic  matter  serve  in  the 
soill 
A.  It  supplies  the  organic  food  which  plants  draw 
from  the  soil  through  their  roots. 

Q.  Do  plants  draw  much  of  their  organic  food  from 
the  soil  ? 
A.  The  quantity  they  draw  from  the  soil  varies  with 
the  kind  of  plant,  with  the  kind  of  soil,  and  with  the  sea- 
son; but  it  is  always  considerable,  and  is  necessary  to 
the  liealthy  growth  of  the  plant. 

Q.  Jf  plants  always  draw  this  organic  matter  from  the 
soil,  will  the  soil  not  become  gradually  poorer  and 
less  productive  1 
A.  It  will,  if  badly  managed  and  constantly  cropped. 
Q.   Then  how  can  you  keep  up  the  supply  1 

A.  By  ploughing  in  green  crops, — by  growing  clo- 
vers and  other  i)lants  which  leave  long  roots  in  the  soil, — 
by  restoring  all  the  hay  and  straw  to  the  land  in  the 
form  of  manure, — or  by  laying  down  to  pasture. 

The  teacher  may  illuslrate  this  answer  beneficially,  by  re- 
ferring to  the  practice  in  his  own  or  the  neighboring 
towns,  and  pointing  out  its  advantages  or  defects. 

Q.    IVhence  is  the  inorganic  part  of  the  soil  derivedf 

A.  The  inorganic  part  of  the  soil  is  derived  from  the 
crumbling  down  of  the  solid  rocks. 

The  teacher  will  satisfy  his  pupils — by  drawing  their  at- 
tention to  the  decaying  walls  of  buililings,  to  the  heaps 
of  what  is  called  rotten  rock,  (decomposed  trap  or  whin- 
stone) — of  limestone,  gravel,  &c.  which  are  found  at  the 
foot  of  the  hills — that  rocks  really  do  crumble  down  in 
the  air. 


CHEMISTRY   AND    GEOLOGY.  33 

Q.   Of  what  do  these  rocks  principally  consist  ? 

A.  They  consist  of  more  or  less  hardened  sandstones, 
limestones  and  clays. 

The  teachers  may  exhibit  as  specimens  of 

Sandstone — red  and  white,  or  other  freestones; 
Limestone — chalk  and  blue  or  other  limestones; 
Clays — roofing  slate,  and  the  shale  or  shiver  of  the  coal 
beds. 

Q.  Do  soils  consist  principally  of  the  same  substances^ 

A.  Yes,  soils  consists  principally  of  sand,  clay  and 
lime. 

Q.  ^010  would  you  name  a  soil  which  contained  one  of 
these  substances  in  large  quantity  ? 

A.  If  it  contained  very  much  sand,  I  would  call  it  a 
sandy  soil;  if  much  clay,  a  more  or  less  stiff  clay  soil; 
if  much  lime,  a  calcareous  soil. 

The  teacher  will  explain  the  new  word  calcareous. 
Q.  But  if  the  soil  contained  two  or  more  of  them  in 
large  proportions  how  xcould  you  name  it  ? 

A.  A  mixture  of  sand  and  clay  with  a  little  lime,  I 
would  call  a  loam;  if  much  lime  was  present,  I  would 
call  it  a  calcareous  loam;  and  if  it  were  a  clay  with 
much  lime,  I  would  call  it  a  calcareous  clay. 
Q.    TVhat  do  you  understand  by  light  and  heavy  lands  ? 

A.  Light  lands  are  such  as  contain  a  large  proportion 
of  sand  or  gravel;  heavy  lands,  such  as  contain  much 
clay. 

The  teacher  may  illustrate  this,  by  referring  to  the  dififer- 
ent  kinds  of  land  which  occur  in  the  neighborhood. 

3 


34  CATECHISM    OF   AGRICULTURAL 

Q.   JVhich  of  these  two  kinds  of  land  is  most  easily  and 
cheaply  caltivated  ? 

A.  The  liglit  lands,  called  oflen  also  barley  or  turnip 
soils. 
Q.    lyiiy  are  these  lands  called  barley  or  turnip  soils'! 

A.  Because  they  have  been  found  to  be  peculiarly 
fitted  for  the  growth  of  barley  and  of  turni]),  and  other 
green  crops, 

Q.  Do  heavy  or  light  lands  usually  stand  most  in  need 
of  draining"! 

A.  The   heavy   clay   lands   retain   water    most,  and 
should  therefore  be  generally  drained  first. 
Q.   Do  light  lands  not  require  draining  1 

A.  Yes,  though  dry  at  tlie  surface,  such  soils  are  of- 
ten wet  beneath,  and  would  pay  well  for  draining. 

The  teacher  may  illustrate  this,  by  referring  his  pupils  to 
what  they  may  see  on  the  sea  beach,  or  on  the  banks  of 
e  river,  where  the  surface  of  the  sand  may  be  dry  and 
drifted  by  the  wind,  while  it  is  quite  wet  a  few  inches 
below. 

Q.   7b  what  depth  would  you  drain  your  lands. 

A.  If  I  could  get  a  fall  I  woidd  never  have  my  drains 
sballower  than  30  inches. 
Q.    JVhy  loould  you  put  them  so  deep  ? 

A.  Because  the  deeper  tlie  dry  soil  is  made,  the  deep- 
er the  roots  can  go  in  search  ol  fond. 
Q.  Can  you  give  me  any  other  reason  ? 

A.  Yes,  when  my  drains  are  so  deep  I  can  go  down 
20  or  22  inches  with  my  subsoil  plough,  wjtliout  any 
risk  of  injuring  them. 


CHEMISTRY    AND    GEOLOGY.  35 

Q.  Does  draining  serve  any  other  purpose  besides  that 
of  carrying  off  the  water  from  the  land? 
A.  Yes,  it  lets  in  the  air  to  the  subsoil,  and  allows  the 
rain  water  to  sink  down  and  wash  out  of  it  any  thing 
wliich  may  be  hurtful  to  the  roots  of  plants. 
Q.  Do  such  hurtful  substaiices  often  collect  in  the  sub- 
soil? 
A.  Yes,  very  often,  and  crops  which  look  well  at  first, 
often  droop  or  fail  altogether  when  their  roots  get  down 
to  the  hurtful  matter. 

The  teacher  may  illiislrale  this  answer  by  referring  fo  the 

layers  of   iron-ochre,  or  part,   which  in  many  districts 

are  met  with  in  the  subsoil,- — and  to  such  curious  facts 

as  that  observeil  in  the  East  of  Fife,  where  the  beans 

and  oats,   which  look  well  up  to  April  or  May,  often 

blacken  and  fail   in  June  or  July,   when  the  roots  get 

down  to  the  ochrey  subsoil.     It  is  the  local  saying  when 

this  hai'pens — that  the  beans  or  oats  have  gone  to  Auchter- 

muchty — a  fair  being  helil  there  about  the  time  when  the 

beans  usually  fail. 

Q.    Why  are  many  of  the  heaviest  clays  in  the  country 

laid  down  to  permanent  pasture  ? 

A.  Because  the  expense  of  ploughing  and  working 

these  soils  is  so  ^reat,  that  the  value  of  the  grain  reaped 

from  them  is  not   sufficient  to  pay  the  farmer  for  his 

trouble. 

Q.  Hon  could  these  heavy  clay  lands  be  rendered  lighter 
and  more  cheap  to  work  ? 
A.  By  draining,  subsoil  ploughing,  and  by  the  addi- 
tion of  lime  or  marl  when  it  is  required. 

The  teacher  will  here  explain  to  his  pupils  the  diSerence 


36  CATECHISM   OF   AGEICULTURAL 

between  common  ploughing,  which  merely  turns  over  the 
surface  soil, — subsoil  ploughing,  which  only  stirs  and 
loosens  the  subsoil, — and  trench  ploughing  or  trenching, 
which  brings  the  subsoil  to  the  surface. 

Q.    JVould  the  land  after  this  treatment  also  give  greatei 
crops  of  grain  1 
A.  Yes,  not  only  would  it  be  more  cheaply  worked, 

but  it  would  yield  a  greater  number  of  bushels  of  wheat 

per  acre  than  before. 

Q.    Would  this  increase  be  s^ifficient  to  pay  the  cost  of 
draining  ? 
A.  Yes,  the  cost  of  draining  clay  lands  is  generally 

paid  back  in  three,  or,  at  the  utmost,  in  five  years,  and 

the  crops  still  continue  greater  than  before. 


V. — OF    THE    IXOKGANIC    FOOD    OF    PLANTS. 

Q.  What  are  the  purposes  served  by  the  inorgan  ic  part 
of  the  soil  ? 
A.  The  inorganic  or  earthy  part  of  the  soil  serves  two 
purposes :  first,  it  serves  as  a  medium  in  which  the  roots 
can  fix  themselves,  so  as  to  keep  the  plant  in  an  upright 
position;  and  Seconal,  it  supplies  the  plant  with  inorganic 
food. 

Q.   The  inorganic  part  of  the  soil  consists  chiefly  of 
sand,  clay  and  lime;  does  it  contain  no  other  sub- 
stances ? 
A.  Yes,  it  contains  small  quantities  of  eight  or  nine 
other  substances. 
Q.  Name  these  substances. 

A.  Potash,  soda,  magnesia,  oxide  of  iron,  oxide  of 


CHEMISTRY    AND    GEOLOGY.  37 

tniinganese,  sulphuric  acid,  phosplioric  acid,  and  chlo- 
rine. 

Q.  Are  not  these  the  same  substances  tvhich  exist  in  the 
ash  or  inorganic  part  of  plants  ? 
A.  Yes,  the  same  substances  exactly — only  they  form 
a  much  larger  proportion  of  the  soil  than  they  generally 
do  of  plants. 

Q.  Do  you  understand  then  where  plants  obtain  all  the 
inorganic  matters  they  contain  ? 
A.  Yes,  they  obtain  them  from  the  soil  only. 
Q.    fyhy  can  they  not  obtain  them  from  the  air  ? 

A.  Because  potash,  soda,  magnesia,  &c.  do  not  exist 
in  the  air. 
Q.  How  does  this  earthy  matter  enter  into  the  plant  1 

A.  It  enters  by  the  roots. 
Q.  In  what  state  ? 

A.  In  a  state  of  solution.     The  rain  and  spring  wa- 
ters dissolve  them  and  carry  them  into  the  roots. 

Here  the  teacher  will  explain  the  meaning  of  the  new 
words  dissolve  and  solution — showing  how  salt  anil  sugar 
melt  away  or  dissoh'e  in  water,  (orming  cleSLV solutions  of 
salt  or  sugar,  in  which  these  subslances  can  be  recog- 
nized only  by  the  sense  of  taste — but  from  which  they 
may  again   be   obtained  vnchangedj  by  boiling  otf  the 
water. 
Q.  Do  all  soils  contaiii  every  one  of  the  inorganic  sub- 
stances, potash,  soda,  lime,    Sfc,  which  you  have 
mentio7ied  ? 
A.  All  fertile  or  productive  soils  do. 
Q.    fVhij  must  a  fertile  soil  contain  them  aW! 


3S 


CATECHISM    OF    AGEICULTUKAL 


A.  Because  plants  require  them  all  for  their  healthy 

growth. 

Q.  Do  plants  require  them  all  in  equal  proportion  ? 
A.  No.     Plants  must  have  a  certain  small  quantity  of 

each  of  Ihem,  but  they  require  more  of  some  substances 

than  of  others 

The  teacher  may  illustrate  this  question  by  directing  the 
attention  of  his  pupils  (o  the  following  table,  which  he 
shouKl  cause  to  be  copied  upon  a  large  piece  of  cotton 
or  paper,  or  a  black-board,  and  hung  upon  the  wall  of 
his  school-room.  He  can  thus  readily  point  out,  that, 
while  1,000  lbs.  of  red-clover  hay  leave  in  all  75  lbs.  of 
ash  when  burned,  there  are  present  in  this  ash  2S  lbs.  of 
liine,  but  only  20  lbs.  of  potash,  and  less  than  4  lbs.  of 
magnesia, — and  so  on  with  the  ash  of  the  other  kinds 
of  hay  mentioned  in  the  table. 

I. —  Quantity  and  composition  of  the  ash  left  by  1,000 

lbs.  of  hay  from 


Ryegrass 

CLOVtR. 

Lucerne. 

Red. 

White. 

Potash, 

Soila, 

9 

4 

7 

I 
trace 
2S 

^ 

trace 

20 

5} 
28 

3 
trace 

4 

^i 

31 
6 

1; 

is" 
H 

5 
2 

13i 
6 

48 

i 

13 
3 

Lime,        

Magnesia 

Oxide  of  iron, 

Silica, 

Sulphuric  acid,. .  . 
Phosphoric  acid,  . 

53  lbs. 

74]  lbs 

89i  lbs 

94^  lbs 

CHEMISTRY    AND    GEOLOGY.  39 

This  table  will  suggest  to  the  teacher  many  inslructive 
questions — which  his  pupils  will  readily  untlcrslanil  and 
answer,  when  they  have  the  table  hanging  before  them. 

Q.  Are  those  substances  which  are  present  in  the  plant 

in    such   minute  quantities,  really  necessary  to  ita 

growth  ? 

A.  They  appear  to  be  all  equally  necessary — just  as 

the  few  ounces  of  nails  or  glue  are  as  necessary  to  the 

joiner  in  making-  a  box,  as  the  many  pounds  of  wood 

which  the  box  contains. 

Q.    Suppose    a   soil   to    be  entirely  destitute  of  one  of 
these  substances,  what  would  happen"! 
A.  Good  crops  would  not  grow  upon  it. 
Q.  Suppose  it  to  contain  a  large  supply  of  all  the  others, 
but  only  a  small  supply  of  some  one  of  these  sub- 
stances, what  would  happen  1 
A.  Those  plants  would  grow  well  upon  it  which  re- 
quire only  a  small  quantity  of  that  one  substance, — but 
those    which   require   a   large  quantity  of  it  would  be 
stunted  and  unhealthy. 
Q.   Give  me  an  example. 

A.  If  the  land  contained  little  lime,  it  might  grow  a 
good  crop  of  rye-grass,  and  yet  not  be  able  to  grow  a 
good  crop  of  lucerne. 

By  refei  ring  to  the  above  table,  the  teacher  may  exercise 
the  uiuleislaniling  ol  his  pupils  by  asking  for  other  ex- 
amples of  a  similar  kind,  which  the  intelligent  boy 
will  readily  give  by  considering  the  numbers  on  the  ta- 
ble.    Thus  he  may  say,  lucerne  requires  more  phospho- 


40  CATECHISM    OF    AGKICTJLTT7EAL 

ric  acid  than  rye- grass  does;  therefore  if  there  be  little 
phosphoric  acid  in  the  soil,  lucerne  will  not  grow  so 
well  upon  it  as  rye-grass  would  do,  and  so  on. 
Other  tables  of  a  similar  kind  also  the  teacher  may  make 
use  of,  which  he  will  find  in  the  author's  "  Elements/' 
and  especially  in  his  "Lectures on  Agricultural  Chemiitry 
and  Geology." 

Q.   Suppose  a  soil  to  be  destitute  of  a  considerable  num- 
ber  of  these  different  inorganic  substances, — what 
icould  happen  ? 
A.  It  would  refuse  to  grow  good  crops  of  any  kind 
whatever.     It  would  be  naturally  barren. 
Q.  Are  any  soils   known   to  exiit  which  are  naturally 
barren  or  naturally  fertile. 
A.  Yes;  some  large   tracts  of  country  which   have 
never  been  cultivated  by  man,  are  known  to  he  naturally 
fertile,  and  others  naturally  barren. 
Q.  ffjw  is  the  natural  difference  between  such  soils  ex- 
plained .' 
A.  In  the  fertile  soils  all  those  inorganic  substances 
exist,  which  our  cultivated  crops  require ;  in  the  barren 
soils  some  of  these  substances  are  wholly  wanting. 

This  answer  the  te.icher  will  illustrate  by  a  reference  tn 
the  following  table,  which  he  will  also  hang  up  on  the 
wall  of  his  school-room.  It  will  do  mnch  good,  indeed, 
to  have  this  and  the  preceding  table  suspended  as  pernva- 
nent  fixtures  in  the  room.  The  youngest  child  will  soon 
become  familiar  in  this  way  with  all  the  names, —  so  dif- 
ficult for  grown-up  farmers  to  recollect. 


CHEMISTRY    AND    GEOLOGY. 


41 


II. —  Composition  of  soils  of  different  degrees  of  fertility 


Organic  matter, 

Silica  (in  tlie  sand  anil  clay,) 

Alumina  (in  the  clay,) 

Lime, 

Magnesia, 

Oxide  of  iron, 

Oxide  of  manganese, 

Potash, 

Soda,        )    .  •   «  ,. 

„,,  '.      >  chiefly  as  com.  salt. 
Chlorine  )  ^ 

Sulphuric  acid, 

Phosphoric  aciil, 

Carbonic  acid,  (combined  with 

the  lime  and  magnesia,) 

Loss, 


Fertile,     Fertile, 
without       with 
Manure.   Manure, 


97 

648 

57 

59 

81 

61 

1 

2 

<4 

^2 


1000 


50 
833 
51 
18 
8 
30 
3 
trace 


1000 


40 

778 

91 

4 


1000 


The  soil,  of  which  the  composition  is  given  in  the  first 
column,  had  produced  crops  for  60  years  without  ma- 
nure,— and  still  contained  a  sensible  quantity  of  all  tlie 
substances  required  by  plants.  That  in  the  second  column 
produced  good  crops  when  regularly  manured, — it  teas 
in  want  of  three  or  four  substances  only,  u'hich  were  given 
to  it  by  tite  manure.  The  third  was  hopelessly  barren, — 
it  was  in  want  of  many  substances  which  ordinary  manur- 
ing could  not  supply. 

Q.  May  a  soil  be  barren  though  it  contains  all  the  sufr- 
stances  which  plants  require  ? 
A.  Yes,  if  it  contain  a  very  large  proportion  of  some 


42  CATECHISM    OF    AGRICnLTURAI, 

one,  such  as  oxide  of  iron,  which  in  great  quantity  is  in- 
jurious to  the  soil. 
Q.  How  would  you  improve  a  soil  oj  this  kind? 

A.  I  would   thorough-drain  and  subsoil   it,  that  the 
rains  might  sink  through  it  and  wash  out  the  injurious 
matter,  and  I  would  lime  it  if  it  required  lime. 
Q.  May  a  soil  which  is  naturally  fertile  be  rendered 
barren  by  continued  cropping  ? 

A.  Yes,  if  the  same  kind  of  cropping  be  carried  on  for 
a  long  time,  the  land  will  gradually  become  less  and  less 
productive. 
Q.    Give  me  an  example. 

A.  If  the  same  field  be  cropped  year  after  year  with 
wheat  or  oats,  it  will  at  last  become  unable  to  grow  either 
of  these  crops. 
Q.    Why  is  this  1 

A  Because  these  crops  draw  certain  substances  from 
(he  soil  in  great  abundance, — and  after  a  number  of 
years  the  soil  cannot  furnish  these  substances  in  suffi- 
cient quantity. 

Q.    What  substances  does  grain  especially  draw  from 
the  soil  ? 

A.  The  seed  of  our  grain  crops  especially  exhausts 
the  soil  o{  phosphoric  acid,  and  o{  magnesia. 

The  teacher  will  illustrate  this  by  a  reference  to  the  fol- 
lowing table,  repi-csentinj  the  composition  of  the  ash  of 
the  several  kinds  o(  grain  usually  grown  in  this  country 
— exclusive  of  the  straw. 


CHEMISTRY    AND    GEOLOGY 


43 


III.   Composition  of  the  ash  of  wheat,  oats,  barley  and 
rye. 


Wheat. 

Oats. 

Barley. 

Rye. 

Potash  ami  soila, . . . 
Lime, 

37.72 
1.93 
9.60 
1.36 
? 

49.32 
0.17 

19.12 
10.41 
9.98 
5.08 
1.2.i 
46.26 

""s'.oY 

20.70 

3.36 
10.0.5 

1.93 

? 
40.63 

0.26 
21.99 

37.21 
2.92 

10.13 
0.82 
? 

47.29 
1.46 
0.17 

Oxide  of  iion, 

Oxiile  of  manganese, 
Phosphoric  aciil,.. . 

Sulphuric  aciil 

Silica, 

100. 

98.87 

9S.92 

100. 

The  teacher  will  point  especially  to  tae  large  quantity  of 
phosphoric  acid  in  the  above  table,  and  will  explain, 
that,  as  the  grain  takes  out  more  of  L\^  than  of  any  other 
substance  from  the  soil,  numerous  successive  crops  of 
grain  must  exhausi  .t  of  this  more  than  of  any  other  sub- 
stance. 

Q.  How  iDOuld  you  remedy  such  special  exhaustion  ? 

A.  By  returning  to  the  soil  (lie  particular  substances 
my  crops  had  tnken  out. 

Q.  Hoio  would  you  return  the  phosphoric  acid  for  in- 
stance ? 

A.  I  would  apply  bone  dust,  or  g-uano,  or  some  other 
manure  in  which  phosphoric  acid  abounds. 
Q.  But  with  any  kind  of  cropping  may  not  a  fertile  soil 
be  at  length  made  unproductive  ? 

A.  Yes,  if  the  crops  are  carried  off' the  land,  and  what 
they  draw  from  the  soil  is  not  again  restored  to  it. 
Q.  Hoiv  is  this  explained  ! 


44  CATECHISM    OF    AGRICULTUKAL 

A.  Every   crop  takes  away  from  the  soil  a  certain 
quantity  of  those  substances  which   all  plants  require. 
If  you  are  always  taking  out  of  a  purse  it  will  at  last  be- 
come empty. 
Q.  Then  you  liken  exhausted  land  to  an  empty  purse  ? 

A.  Yes,  the  farmer  takes  his  money  out  of  the  land, 
and  if  he  is  always  taking  out  and  putting  nothing  in,  it 
must  at  last  become  empty  or  exhausted. 
Q.  £ut  ij  he  puis  something  into  the  soil  now  and  then, 
he  may  continue  to  crop  without  exhausting  it  ? 

A.  Yes,  if  he  put  in  the  proper  substances,  in  the  pro- 
per quantities,  and  at   the  proper  time,  he  may  keep 
up  the  fertility  of  his  land — perhaps  forever. 
Q.  How  much  of  every  thing  must  the  farmer  pal  into 
his  land  to  keep  it  in  its  present  condition  ? 

A.  He  must  put  it  in  at  least  as  much  as  he  takes  out. 
Q.   7b  make  his  land  belter,  how  much  must  he  put  in  ? 

A.  He  must  put  in  more-  than  he  takes  out. 
Q.  But  if  he  is  to  put  into  tite  land  as  much  or  more 
than  he  takes  out,  where  is  his  profit  to  come  from? 

A.  His  profit  consists  in  this,  that  he  takes  off  the  land 
what  he  can  SiU  for  much  money,  and  he  puts  in  what 
he  can  buy  for  comparatively  little  money. 
Q.  Hoiv  do  you  mean  ? 

A.  I  mean  that  if  I  sell   my  oats   and   hay,  I  get  a 

much  higher  price  for  them  than  1  afterwards  give  when 

I  buy  tliem  back  again  in  the  form  of  horse  dung. 

Q.   Then  the  farmer   can   really  afford  to  pat  as  much 

upon  his  land  as  he  takes  off,  and  yet  have  a  profit  ? 

A    He  can.     He  puts  in  what  is  cheap,  and  takes  oCF 
what  is  dear. 


CHEMISTRY    AND    GEOLOGY.  45 

The  teacher  may  avail  himself  of  this  occasion  to  point 
out  how  beaulifully  anil  bountifully  the  eaith  anil  Iho 
plant  are  maile  to  work  into  the  hands  of  the  practical 
farmer,  by  converting  into  valuable  produce  what  he 
lays  on  in  the  form  of  a  worthless  refuse — and  how  they 
always  do  most  for  the  skilful,  the  prudent,  and  the  in- 
dustrious. 

Q.    JVIiat  do   you  call  the   substances  which  the  skilful 
farmer  thus  puts  into  his  land  ? 
A.  Tlicy  are  called  manures, — and  when  putting  them 
in,  tlie  farmer  is  said  to  manure  his  soil. 


VI. — OF    THE    MANURING      OF    THE    SOIL.. 

Q.    JVhat  is  a  manure  ? 

A.  Any   thing  lliat  furnishes  food  to  plants  may  be 
called  a  manure. 
Q.  How  many  principal  kinds  of  manure  are  there  ? 

A.  There  are  three  principal  kinds,- — vegetable  ma- 
nures, animal  manures,  and  mineral  manures. 
Q.    What  do  you  mean  by  vegetable  manures  ? 

A.  By   vegetable   manures,   I   mean   those    parts  of 
plants  which  are  usually  buried  in  the  soil  for  the  pur- 
pose of  making  it  more  productive. 
Q.  Name     the    most    important    of  the   vegetable   ma- 
nures. 

A.  Grass,  clover,  straw,  hay,  potato-tops,  rape-dust, 
&c. 
Q.  Is  green  grass  ever  used  for  manuring  the  soil  ? 

A.  Yes,  the  soil  is   manured  with  green  grass,  when 
grass  land  is  ploughed  up. 


46  CATECHISM    OF    AGRICULTURAL 

Q.    fVould  you  bury  the  sods  deep  if  you  were  ploughing 
up  grass  land  ? 

A.  No,  I  would  keep  the  sods  so  near  the  surface  that 
the  roots  of  the  young  grain  could  feed  upon  the  de- 
caying grass. 

Q.  jire  any  other  plants  ploughed  in  green  for  the  pur- 
pose of  manuring  the  soil  ? 

A-  Yes,  clover,  buck  %¥heat,  rape,  rye,  and  in  some 
places  even  young  turnips  are  ploughed  in  green  to  en- 
rich the  soil. 

Q.  Into  what  kind  of  soils  would  you  plough  in  a  green 
crop  ? 

A.  Into  light  and  sandy  soils,  and  into  such  as  contain 
very  little  vegetable  matter. 
Q.  Is  not  sea  weed  or  sea- ware  a  very  valuMc  manure  ? 

A.  Yes,  wherever  sea-weed  can  be  obtained  in  large 
quantity,  it  is  found  to  enrich  the  soil  very  much. 
Q.  How  is  it  employed  1 

A.  It  is  either  spread  over  the  land  and  allowed  to  rot 
and  sink  in,  or  it  is  made  into  a  compost,  or  it  is  put  in- 
to the  potato  drills  in  the  fresh  state. 
Q.    When  used  in  this  last  way  does  it  give  large  crops 
oj  potatoes  ? 

A.  Yes,  on  the  east  and  west  coasts  of  Scotland  it  is 
said  to  give  large  crops  of  potatoes,  but  of  inferior 
quality. 

Q.  How  would  you  prefer  to   make  a  compost  of  sea- 
weed ? 

A.  I  would  mix   the   sea-weed   vfith  earth  and  with 


CHEMISTEY    AND    GEOLOGY.  47 

shell-sand  or  marl,  if  they   were   to   be  had,  and  turn  it 
over  once  or  twice  before  using  it. 

Q.  Are  there  any    common    f;reen  vegetables  that  art 
ploughed  in  with  advantage  I 
A.  Yes,  potato-tops  dug  in,  or  turnip-tops,  when  the 
roots  are  pulled,  make  the  next  year's  grain  better. 
Potato  or  lurnip  lops  ploughed    in    make   the   succeeding 
barley  or  wheat  crop  so  much  belter,  that,  about  Edin- 
burgh, the  turnip  tops   are    reckoned  equal  to  8  tons  of 
farm-yard  manure,  or  £2  an  acre.     It  is  said,  however, 
that  the  clover  which  succeeds  the  grain  is  worse  when 
(he  tons  have  been    ploughed    in, — that   it  is  sicklVj  and 
sometimes  fails  altogether. 
Q.  Hoxv  can  you  get  the  largest  quantity  of  green  ma- 
nure in  the  form  of  potato-tops  ? 
A.  By  pulling  off  the   blossoms,  the  tops  are  kept  in 
a  green  state  till  the  potatoes  are  dug  up,  and  thus  give 
much  green  manure. 

Q.  In  what  form  is  hay  usually  employed  as  a  manured 
A.  Hay  is  usually  given  to  the  stock,  and  afterwards 
put  upon  the  land  in  the  shape  of  their  dung. 
Q.  In  what  form  is  straw  used  as  a  manure  ? 

A.  Straw  in  some  places  is  given  to  the  cattle — in 
other  places  it  is  partly  given  to  the  cattle  and  partly 
trodden  among  the  litter — wUile  in  places  again,  where 
few  cattle  are  kept,  it  is  sometimes  rotted  with  water 
and  a  little  cow  dung,  and  put  on  the  land  in  a  half-fer- 
mented state. 

Q.  In  what  state  of  fermentation  would  you  prefer  put- 
ting your  straw  into  the  land  ? 
A.  That  would  depend  upon  the  kind  of  land. 


^  CATECHISM    OF    AGKICULTURAL 

Q.   Suppose  1/ow  had  to  manure  light  land  for  a  green 
crop  ? 

A.  Then  I  would  like  to  have  my  straw  pretty  well 
fermented  and  mixed  with  the  droppings  of  a  good  ma- 
ny cattle. 

Q.  £ut   suppose   you,  icere  manuring  heavy  clay  land 
during  the  naked  fallow  before  a  crop  of  iL>heat  ? 

A.  I  would  then  rather  have  my  straw  more  loose  and 
unfermented.     It  would  help  to  keep  my  land  open. 

This  general  nile  may  not  apply  to  all  even  of  our  heavy 
clay  lands.  Even  stiff  clays  vary  in  quality,  anil  circum- 
stances may  render  inexpedient  in  some  localities  what, 
as  a  general  practiccj  is  the  best  that  can  be  recommen- 
ded. 
Q.    What  are  rape-cake  and  rape-dust  ? 

A.  Rape-cake  is  the  refuse  that  remains  when  rape- 
seed  is  crushed  in  the  mill  to  squeeze  out  the  oil.     When 
Ihe  cake  is  crushed  it  is  called  rape-dust. 
Q.  Now  is  rape-dust  applied  as  a  manure  ? 

A.  It  is  applied  to  turnips  or  potatoes  either  in  place 
of  the  whole  or  of  a  part  only  of  the  common  farm- 
yard dung — and  it  is  in  many  parts  of  the  country  ap- 
plied with  great  profit  as  a  top-dressing  to  the  young 
wheat  in  spring. 
Q.    What  are  the  most  important  animal  manures  1 

A.  The  blood,  flesh,  bones,  hair,  wool,  and  the  dung 
and  urine  of  animals,  and  the  refuse  of  fish. 
Q.  In  li  hat  form  is  blood  usually  employed  as  a  vianure  t 

A.  In  this  country  it  is  usually  mixed  up  with  other 
refuse  in  the  dunghills  of  the  butchers.     In  other  coun- 


CHEMISTRY    AND    GEOLOGY.  49 

tries  it  is  dried  and  applied  as  a  top-dressing,  or  drilled 
in  with  the  seed.     It  is  one  of  the   most  powerful  ma- 
nures. 
Q..  How  is  flesh  employed  as  a  manure  1 

A.  The  ilesh  of  dead  horses,  cows,  and  dogs  buried 
in  soil  or  saw  dust,  with  a  little  marl,  makes  a  most  en- 
riching compost. 

Q.  In  what  form  are  bones  usually  employed  as  a  ma- 
nure ? 

A.  Bones  are  crushed   in  mills,  and  then  sifted  into 
the  various  sizes   of  inch  bones,   half-inch   bones,  and 
dust. 
Q.  In  which  of  these  forms  do  they  act  most  quickly! 

A.  They  act  most  quickly  in   tlie   form  of  dust,  but 
tliey  do  not  act  for  so  long  a  time. 
Q.   To  what  crops  are  they  most  usually  applied  ? 

A.  Bones  are  most  profitably  employed  on  light  or  on 
well-drained  lands,  instead  of  the  whole  or  of  a  part  of 
the  farm-yard  manure.  When  employed  without  farm- 
yard manure,  they  are  often  mixed  with  wood  ashes, 
and  drilled  in  with  Ihe  turnip  seed. 

Q.    Would  you  raise  all  your  turnip  crops  with  bones 
alone  ? 

A.  No,  if  I   raised   one   crop   of  turnips  from  bone* 
alone,  I  would  raise  the  next  crop  on  the  same  field  witk 
farm-yard  manure  alone — if  I  could  get  it. 
Q.  ^re  bones  ever  applied  to  grass  lands  ? 

A.  Yes,  to  grass  lands  that  have  long  been  pastured 
by  growing  stock,  or  for  dairy  purposes,  as  in  Cheshire, 
they  have  been  applied  with  great  profit.     Even  when 


60  CATECHISM    OF    AGRICULTURAL 

the  grass  lands  are  wet,  the  bones  have  produced  re- 
markable benefits. 
Q.    What  do  hones  consist  of! 

A.  Bones  consist  of  glue  or  gelatine,  which  maybe 
partly  extracted  by  boiling  them  in  water — and  of  bone- 
earth,  which  remains  behind  when  bones  are  burned. 

Here  the  teacher  may  burn  a  small  splinter  of  bone  in  the 
flame  of  a  lamp  or   canille,    anil    show    that  though  the 
organic    part  (the    gelatine)  burns  away,  the  inorganic 
part  or  bone-earth  (phosphate  of  time)  remains  behind. 
Q.  Is  the  glae  ot  gelatine  of  bones  a  good  manure  ? 

A.  Yes,   it   is   a   powerful   manure.     It  assists  very 
much  in  pushing;  forward  the  youn.:  turnip  plant,  when 
this  crop  is  raised  by  the  aid  of  bones. 
Q.    What  docs  bone-earth  o^  phosphate  of  lime  consist  of! 

A.  It  consists  of  phosphoric  acid  and  lime. 
Q.  Does  this  earth  of  bones  act  as  a  manure  1 

A.  Yes,  because  all  plants  contain,  and  therefore  re- 
quire for  their  healthy  growth  a  certain  quantity  of  lime 
and  phosphoric  acid  (see  above,  Table  I.  p.  38,  and  III. 
p.  43.) 
Q,    Why  do  old  dairy  pastures  especially  require  bones  ? 

A.  Because  milk  and  cheese  contain  bone-earth,  and 

.  if  these  be  carried  away  and  sold  off  the  farm,  the  land 

is  robbed  by  degrees  of  this  bone-earth,  more  tlian  of 

»ny  other  substance.     Only  those  grasses  can  then  grow 

which  require  little  bone-earth. 

Every  ten  gallons  of  milk  contain  about  half  a  pound  of 
bone-earth.  A  cow,  therefore,  which  gives  twenty 
quarts  a-day,  takes  about  two  pounds  of  bone-earth  from 


CHEMISTRY  AND  GEOLOGY.  51 

the  soil  every  week.     To  return  these  two  pounjs  to  the 
soil  three  pounds  of  bone-dust  are  required. 
Q.  jlnd  what  effect  follmes  from  adding  the  bones  1 

A.  The  bones  supply  the  bone-earth  of  which  the 
land  had  been  robbed.  New  grasses  then  spring  up 
which  contain  much  bone-earth,  and  these,  when  eaten 
by  the  cow,  produce  milk  in  greater  abundance  and 
richer  in  cheese. 
Q.  ^re  bones  applied  in  any  other  form  ? 

A.  Yes,  they   are   sometimes  dissolved  in  sulphuric 
acid  (oil  of  vitriol.) 
Q.  How  do  you  dissolve  bones  in  sulphuric  acid  ? 

A.  About  equal  weights  of  bone-dust  and  of  acid  are 
taken.  Tlie  acid  is  diluted  with  three  times  its  bulk  of 
water  and  poured  upon  the  bones,  and  the  mi.xture  is 
stirred  occasionally  for  two  or  three  days. 

The  teacher  may  show  how  this  is  done,  and  explain  that 
the  liquid  oblained  may  either  be  further  diluted  with 
thirty  times  its  bulk  of  water  and  applied  with  a  water- 
cart,  or  may  be  dried  up  with  powdered  charcoal,  peat, 
saw-dust,  or  soil,  and   drilled    in   as  bones  usually  are. 
The  relative  proportions  of  bones  anil  acid  may  also  be 
varied. 
Q.    What  is  the  advantage  of  thus  dissolving  the  bones  ? 
A.  One  of  the  chief  advantages  is,  that  the  substan- 
ces of  which  the  bones  consist  are  very  miniitely  divi- 
ded.    They  can  thus  enter  more  readily  into  the  roots 
of  plants,  and  a  smaller  quantity  produces  an  equal  effect 
upon  the  crop. 
Q.  Is  hair  much  used  as  a  manure  ? 

A.  No,  hair  is  generally  too  expensive  to  be  used  as 


52  CATECHISM    OF    AGRICULTURAL 

a  manure.     But  in  China,  where  the  people's  heads  are 
all  shaved,  the  shavings  are  collected  lor  manure,  and 
the  sweepings  of  our  hair-cutters'  rooms  might  be  also 
employed  with  profit. 
Q.  In  what  form  is  wool  used  us  a  manured 

A.  In  the  form  of  woollen  rags.  Mixed  with  earth, 
woollen  rags  make  an  excellent  compost.  They  are 
much  used  for  manuring  the  hop  grounds. 

The  teacher  may  here  ilesciibe  the  hop  plant,  and  explain 
the  purpose  for  which  it  is  grown  and  employed  by  the 
brewers. 

Q.    What  kinds   of  animal   dung   are  most  commonly 
employed  as  manures  ? 

A.  Night-soil,  horse  dung,  cow  dung,  slieep's  dung, 
pigs'  dung,  and  birds'  dung. 
Q.    IVhich  of  these  is  the  most  valuable  ? 

A.  In  general,  night-soil  and  birds' dung  are  Ihe  most 
valuable;  next,  horse  dung;  after  that,  pigs'  dung,  and 
lastly,  cow  dung. 
Q.    H'hy  is  night-soil  so  valuable  ? 

A.  Because  men  generally  live  upon  a  mixture  of 
animal  and  vegetable  food,  which  renders  Ihe  dung 
richer. 

Q.    Why  is  the  solid  part  of  horse  dung  richer  or  hotter 
than  cow  dung  ? 

A.  Because  the  horse  void -^  little  urine  compared  with 
the  cow. 
Q.    IFhat  IS  the  principal  objection  lousing  pigs'  dungi 

A.  The  disagreeable  smell  and  taste  it  is  said  to  give 
to  the  crops  raised  from  it. 


CHEMISTRY    AND    GEOLOGY.  53 

Q.    fVhat  is  the  best  way  of  using  pig's  dung  1 

A.  The  best  way  is  to  make  it  into  a  compost,  or  to 
mix  it  with  the  dung  of  other  animals. 
Q.    Wliy  is  cow  dung  colder  and  less  liable  to  fermeiU 
than  most  other  kinds  of  dwng  ? 

A.  Because  the  large  quantity  of  urine  voided  by  the 
cow,  carries  off  a  great  proportion  of  that  which  would 
otherwise  tause  it  to  ferment. 

Q.  In  what  respect  does  the  mixed  dung  of  animals  dif- 
fer from  the  food  on  which  they  live  ? 

A.  It  differs  principally  in  containing  a  less  propor- 
tion of  carbtin,  and  a  greater  proportion  of  nitrogen  than 
the  food  they  have  eaten. 
Q.  How  comes  it  to  contain  less  carbon  ? 

A.  Because  animals  throw  off  a  large  quantity  of  the 
carbon  by  their  breathing. 

Q.  In  what  form  does  the  carbon  of  the  food  come  off 
from  the  lungs  during  breathing  ? 

A.  In  the  form  of  carbonic  acid  gas,  (see  figs.  9 
and  10.) 

Q.  //oi«  much  carbon  does  a  man  give  off  in  this  form 
from  his  lungs  in  a  day. 

A.  A  full  grown  man  gives  off  about  half  a  pound  in 
a  day,  and  a  cow  or  a  horse  eight  or  ten  times  as  much. 
Q.   Does  all  the   nitrogen   of  the  food   remain   in  the 
mixed  dung  and  urine  of  animals  ? 

A.  Yes,  nearly  all  the  nitrogen  remains — mixed  with 
a  smaller  quantity  of  carbon  than  was  in  the  food. 
Q.  Is  this  larger  proportion  of  nitrogen  the  cause  of 
the  greater  activity  of  the  dung  of  animals  ? 

A.  Yes,  it  is  one  of  the  principal  causes. 


54  CATECHISM    OF    AGRICULTURAL 

Q.    What  form  does  this  nitrogen  assume  during  the 
fermentation  of  animal  manures  ? 

A.  It   assumes,  foi  the  most  part,  the  form  of  am- 
monia. 
Q.    ff^hat  is  ammonia'? 

A.  Ammonia  is  a  kind  of  air  which  has  an  exceed- 
ingly strong  smell, — the  common  hartshorn  of  the  shops 
is  merely  water  impregnated  with  this  gas. 

Here  the  teacher  may  exhibit  a  bottle  of  tiartshorn  or  of 
smelling  salts,  (carbonate  of  ammonia.)  and  nial^e  his  pu- 
pils acquainted  with  ttie  smell  of  ammonia. 
Q.    Under   what    circumstances   is   aminonia  produced 
naturally  ? 

A.  It  is  produced  in  fermenting  compost  or  manure 
heaps,  and  in  fermenting  urine,  and  ii  is  the  cause  of  the 
smell  perceived  in  hot  stables. 
Q.  How  can  you  detect  the  presence  of  this  ammonial 

A.  By  dipping  a  rod  or  feather  in  vinegar,  and  holding 
it  over  the  dung  heap  or  in  the  stable,  when,  if  ammonia 
is  present  in  the  air,  white  fumes  will  become  visible. 

Here  the  teacher  will  show  this  experiment,  by  dipping:  a 
glass  rod  or  feather  into  vinegar,  or  into  muriatic  acid, 
and  holding  it  over  the  mouth  of  his  hartshorn  bottle, 
when  white  fumes  will  become  visible,  showing  that 
ammonia  is  escaping  in  the  form  of  gas 

Q.    What  does  ammonia  consist  of? 

A.  Ammonia  consists  of  the  two  gases,  nitrogen  and 
hydrogen. 

14  lbs.  of  nitrogen  and  3  lbs.  of  hydrogen,  make  17  lbs.  of 
ammonia. 


CHEMISTRY    AND    GEOLOGY.  55 

Q.  How  does  this  ammonia  enter  into  the  roots  of  plants, 
when  it  is  formed  in  the  manure  7 
A.  It  is  dissolved  in  the  soil  by  water,  and  is  then 
sucked  in  by  the  roots. 

Q.    What  substances  are  formed  in  plants  by  the  aid  of 
this  aninumia  ? 
A.  The  glulen  and  other  substances  containing  nitro 
gen  are  formed  by  the  aid  of  this  ammonia. 
Q.  Is  this  ammonia,  then,  a  very  important  ingredient 
in  the  manures  1 
A.  Yes,  because  nitrogen,  in  some  shape  or  other,  is 
absolutely  necessary  to  the  growth  of  plants. 
Q.   In  which  part  of  the  manure, — the  solid  or  the  liquid 
part, — is  this  ammonia  produced  in  greatest  abun 
dance  ? 
A.  It  is  produced  in  the  greatest  abundance  in  the  li- 
quid part,  especially  of  cow  dung. 

Q.  Is  it  7iot  of  great  importance,  therefore,  to  preserve 
this  liquid  part  ? 
A.  Yes,   it  is  of  the    greatest   possible  importance, 
though  it  is  too  often  allowed  to  run  to  waste. 
Q.  How  would  you  collect  the  liquid  manure  of  your 
farm-yard  ? 
A.  I  would  make  a  large  tank  or  cistern  in  or  close  by 
my  farm-yard,  in  which  I  would  collect  it. 
Q.   How  would  you  use  this  liquid  manure  ? 

A.  I  would  pump  it  back  occasionally  upon  my  dunj^ 
heaps,  so  as  to  promote  their  fermentation;  or  I  would 
pour  it  upon  ray  compost  heaps. 
Q     PFould  you  not  employ  it  alone  as  a  manure  ? 

A.  Yes,  during  the  spring  and  summer  I  would  dilute 


66  CATECHISM    OF    AGRICULTURAL 

it  with  once  or  twice  its  bulk  of  water,  and  after  it  had 
fermented  for  some  time,  I  would  put  it  on  my  grass 
land,  on  my  young  clover,  or  on  any  other  young  crops, 
with  a  water  cart. 

Q.  Is  there  ajiy  other  liquid  containing  ammonia  which 
might  be  einphiyed  in  a  similar  wayl 

A.  Yes,  the  amaioniacal  liquor  of  the  gas  works,  di- 
luted with  four  or  five  times  its  bulk  of  water,  should  be 
coliecled  and  employed  in  the  same  way  as  the  liquid 
manure  of  the  farm  yard. 
Q.  Does  birds'  dang  form  a  very  valuable  manure  1 

A.  Yes,  pigeons'  dung  especially,  is  a  very  rich  ma- 
nure; and  the  dung  of  sea-fowl  has  lately  been  intro- 
duced into  this  country,  with  great  advantage,  under  the 
name  of  guano. 
Q.   To  what  crops  can  guano  be  profitably  applied  ? 

A.  It  may  be  profitably  employed  as  a  top-dressing 
to  the  young  corn  crops,  or  it  may  be  used  instead  of 
the  whole  or  of  a  part  of  the  farm-yard  dung,  for  the 
turnip  and  potato  crops. 

Q.  In  using  it  for  the  turnip  or  potato  crop,  ought  it  to 
be  allowed  to  come  in  contact  with  the  seed  ? 

A.  No,  it  is  better  either  to  cover  it,  or  to  mix  it  with 
a  quantity  of  earth,  so  as  to  prevent  the  seed  from  touch- 
ing it. 
Q.  Is  it  proper  to  mix  guano  with  quicklime. 

A.  No,  because  the  quicklime  sets  free  the  ammonia 
contained  in  the  guano,  and  causes  it  to  escape  into  the 
air. 

Here  the  teacher  may  mix  a  little   slaked   lime    with  a 


CHEMISTRY    AND    GEOLOGY.  67 

spoonful  of  guano  in  a  wine-glass,  anil  let  his  pupils 
smell  the  ammonia  which  will  come  oif.  Or  he  may 
hold  over  it  a  rotl  or  feather  ttipped  in  vinegar,  and  show 
the  white  fumes.  If  he  have  no  guano,  he  may  use  a 
little  sa/-aOTnio;iiac  or  a  little  sulphate  of  ammania  instead; 
and  may  explain  that  quiclc-hmc  will,  in  the  same  way, 
drive  ofif  ammonia  contained  in  liquid  manure  and  in 
horse  or  farm-yard  dung,  if  it  be  mixed  with  any  of 
these. 

Q.  Is  it  better  to  use  gaano  alone,  or  in  place  of  one- 
half  only  of  the  usual  farm-yard  manure  ? 
A.  It  is  better  husbandry  to  use  it  in  raising  turnips 

and  potatoes,  mixed  witli  one-half  manure. 

Q.    fVhy  is  it  better  husbandry  ? 

A.  Because  the  guano  used  alone,  does  not  supply  to 

the  land  a  sufficient  quantity  of  organic  matter  to  main- 
lain  it  in  the  most  productive  state. 

Q.  HoiB  much  guano  would  you  apply  per  acre  ? 

A.  About  two  cwls.  per  acre  as  a  top-dressing  for  the 

corn  crops,  and  two  or  three  cwts.,  when  used  instead 

of  half  the  dung,  for  potatoes  and  turnips. 

Q.    What  kind  offish  refuse  is  usually  employed  as  a 
manure? 
A.  In  the  curing  stations  the  guttings  and  cleanings 

of  the  herring  and  pilchard,  and  the  heads  of  the  cod  are 

extensively  employed  as  a  manure. 

Q.  How  is  this  refuse  best  used  ? 

A.  The  best  way  is  to  make  it  into  a  compost  with 

earth  and  a  quantity  of  marl,  if  any  of  the  latter  is  at 

hand,  and  to  turn  it  over  once  or  twice  before  using. 

Q.  Name  the  most  important  mineral  manures'! 


58  CATECHISM    OF    AGRICtJLTUKAL 

A.  The  most  important  mineral  manures,  are  nitrate 
of  soda,  sulphate  of  soda,  common  salt,  gypsum,  kelp, 
wood  ashes  and  lime. 
Q.    What  is  nitrate  of  soda  ? 

A-  Nitrate  of  soda  is  a  white  salt-like  (saline)  sub- 
stance, which  is  found  in  the  earth  in  some  parl^  of  Pe- 
ru, and  is  often  applied  with  great  advantage  as  a  top- 
dressing  to  grass  lands  and  to  young  corn. 
Q.    What  does  nitrate  of  soda  consist  oft 

A.  It  consists  of  nitric  acid  and  soda. 

54  lbs.  of  nitric  acid,  and  31  lbs.  of  soda,  form  85  lbs.  of 
nitrate  of  soda. 

The  teacher  may  lake  this  opportunity  of  verbally  explain 
ing  the  kinil  of  (erms  by  which  chemists  denote  combi 
nations  of  the  nitric,  sulphuric,  phosphoric,  and  carbonii 
acids  with  potash,  soda,  lime,  and  magnesia, — that  when 
carbonic  acid  combines  with  any  of  these  substances  it 
forms  a  carbonate,  phosphoric  acid  a  phosphafc,  sulphu- 
ric acid  a  sulpha<c,  nitric  acid  a  nilrafc.  Hence,  that 
phosphate  of  lime  denotes  a  combination  of  phosphoric 
acid  with  lime,  sulphate  of  soda,  a  combination  of  sul- 
phuric acid  with  soda,  and  so  on. 

Q.    What  is  intric  addl 

A.  Nitric  acid  is  a  very  sour  corrosive  liquid,  called 
also  aquafortis.  It  consists  of  the  two  gases,  nitrogen 
and  oxygen. 

14  lbs.  of  nitrogen  and  40  lbs.  of  oxygen  form  54  lbs.  of 
nitric  acid. 
Q.    Upon  what  does  the  beneficial  action  of  nitrate  of 
soda  upon  plants  depend  ? 


CHEMISTRY    AND    GEOLOGY.  59 

A.  Upon  its  supplying  nitrogen  and  soda  to  the  grow- 
ing crops. 
Q.    What  quantify  would  you  lay  upon  an  acre  ? 

A.  From  1  cwt.  to  Ij  cwt.  to  an  acre. 
Q.    What  is  sulphate  of  soda? 

A.  Sulphate  of  soda  is  the  substance  commonly  called 
glauber  salts,  and  consists  of  sulphuric  acid  {oil  of  vit- 
riol,') and  soda.  It  sometimes  produces  good  effects 
when  applied  as  a  top-dressing  to  grass  lands,  to  turnips, 
and  to  young  potato  plants. 

40  lbs.  of  sulphuric  acid  with  31  lbs.  of  soda,  form  71  lbs. 
of  dry  sulphate  of  soda. 
Q.  How  is  common  salt  applied  ? 

A.  Common  salt  may  either  be  applied  as  a  top  dress 
ing,  or  it  may  be  mixed  with  the  farm  yard  or  other 
manure,  or  with  the  water  used  in  slaking  quicklime. 
Q.  In  what  places  is  salt  most  likely  to  be  beneficial  ? 

A.  In  places  that  are  remote  from  the  sea,  or  are  shel 
tered  by  high  hills  from  the  winds  that  pass  over  the  sea. 
Q.  How  do  you  account  for  this? 

A.  Because  the  winds  bring  with  them  a  portion  of 
the  sea  spray,  and  sprinkle  it  over  the  soil  to  a  distance 
of  many  miles  from  the  sea  shore. 
Q.    ffliat  is  gypsum  ?   (plaster  ?) 

A.  Gypsum  is  a  white  substance,  composed  of  sul 
phuric  acid  and  lime;  it  forms  an  e.xcellent  lop  dres- 
sing for  red  clover,  and  also  for  the  pea  and  bean  crop. 

40  lbs.  of  sulphuric  acid  and   28  1-2   lbs.  of  lime   form 
68  1-2  lbs.  of  burned  gypsum. 

40  lbs.  of  acid,   28i   lbs.   of  lime,  18  lbs.  of  water,  form 


60  CATECHISM    OF    AGRICULTURAL 

86|  lbs.  of  unburnetl  gypsum.     Native  or  unbiirneil  gyp- 
sum loses  about    21    per  cent    of  waler  when  healed  to 
dull  redness,  becoming  burned  gypsum. 
Q.    Under  what  circumstances  ouglU  tliese  sail-like  or 
saline  substances  to  be  applied  ? 
A.  They  ought  to  be  applied  in  calm  weather,  in  or- 
der (hat  they  may  be  equally  spread, — and  soon  after  or 
before  rain,  that  they  may  be  dissolved. 
Q.  jfre  mixtures   of  these   substances  sometimes  more 
beneficial  than  any  of  them  applied  singly  ? 
A.  Yes,  a  mixture  of  nitrate   and   sulphate  of  soda 
usually  produces  a   much   more   beneficial   eflfect  upon 
potatoes  than  either  of  them  alone,  and  the  same  is  often 
the  case  with  a  mixture   of  common  salt  and  pypsuni 
when  applied  to  the  bean  crop. 

The  teacher  will  find  some  useful  particulars  upon  this 
point  in  the  author's  Elements  of  Agricultural  Chemistry 
and  Geology,  (fourth  Edition,  page  194),  which  he  may- 
consult  with  advantage,  with  the  view  of  explaining  the 
subject  more  fully  to  his  pupils,  when  he  shall  think  it 
proper  to  do  so. 
Q.    What  is  kelp  ? 

A.  Kelp  is  the  ash  that  is  left  when  sea-weed  is  burned 
in  large  quantities. 
Q.  Can  it  be  employed  usefully  as  a  manure  ? 

A.  Yes,  as  a  top  dressing  to  grass  lands  and  to  young 
grain — or  even  mixed  with  the  manure  for  the  turnip 
and  potato  crop  it  may  be  employed  with  much  advan- 
tage. 

Q.  Has  it  been  generally  employed  as  a  manure  in  Scot- 
land! 


CHEMISTRY    AND    GEOLOGY.  61 

A.  Not  hilherto,  but  there  is  reason  to  believe  that, 
if  fairly  tried,  it  might  be  jirofitably  employed  to  a  large 
extent. 

Q.  Are  woud   ashes   (^or  the  ashes  of  burned  mood)  a 
valuable  manure  ? 

A.  Yes,  sipplied  to  grass  lands  wood  ash  destroys 
moss,  and  increases  their  luxuriance:  upon  young  grain 
and  potatoes  it  produces  a  similar  effect,  and  is  profita- 
bly mixed  with  bones,  rape-dust,  guano,  and  other  ma- 
nures which  are  employed  for  the  turnip  crop. 
Q.    What  does  limestone  consist  of! 

A.  Limestone  consists  of  lime  (juicfc-lime)  in  com- 
bination with  carbonic  acid. 

28  lbs.  of  lime  and  22  lbs.    of  carbonic  acid  make  SO  Ibi. 
of  limestone. 

The  teacher  may  here  revert  (o  the  properties  of  carbonic 
aciii,  and  examine  his  pupils  upon  what  they  had  previ, 
ously  learned  upon  this  subject. 
Q.   JVhat  name  is  given  to  limestone  by  chemists  ? 

A.  It  is  called  by  chemists  carbonate  of  lime. 
Q.  jire  there  not  many  varieties  of  limestone  ? 

A.  Yes, — some  soft,  such  as  chalk, — some  hard,  such 
as  our  common  limestones, — some  of  a  yellow  color, 
like  the  magnesian  limestones,  which  contain  mag- 
nesia,— some  pure  white,  like  the  statuary  marble, — 
some  black,  like  the  Derbyshire  black  marble,  and  so  on. 

Here  it  wouhl  be  advantageous  if  the  teacher  could  exhibit 
some  of  these  or  of  other  varieties  of  limestone. 
Q.    JVhat  is  marl  ? 

A.  Marl  is  the  same  thing  as  limestone,  namely,  car- 


62  CATECHISM    OF    AGRICULTCRAL 

bonate  of  lime,  only   it   is  often   in  the  state  of  a  fine 
powder,  and  often  also  mixed  with  earthy  matter. 
Q.    IVhat  is  shell  sand  1 

A.  Shell  sand  or  broken  sea-shells  is  also  the  same 
tiung,  almost  exactly,  as  common  limestone. 
Q.    Can  these  marls  and  shell  sands  be  applied  with  ad- 
vantage to  the  land  ? 

A.  Yes,  either  as  a  top-dressing  to  grass  lands,  and 
especially  to  sour,  coarse,  and  mossy  grass, — or  they 
may  be  ploughed  or  harrrowed  in  upon  arable  fields, — 
and  especially  they  may  be  applied  with  advantage  and 
in  large  quantity  to  peaty  soils. 
Q.   Can  they  not  be  used  also  in  making  composts  7 

A.  Yes,  mixed  with  earth  and  vegetable  matter,  or 
with  animal  matter,  such  as  fish  refuse,  whale  blubber, 
&c.,  and  even  with  farm-yard  dung,  they  will  often  pro- 
duce very  good  effects. 

Q.  How  would  you  ascertain  the  presence  of  lime  in  a 
soil  or  in  a  substance  supposed  to  be  a  marl  ? 

A.  By  putting  a  little  of  it  into  a   glass  and  pouring 
upon  it  either  vinegar  or   weak  spirit  of  salt  (murialic 
acid.)     If  any  bubbling  up  (effervescence)  appeared,  I 
should  say  that  lime  was  piesent. 
Q.   To  what  would  this  bubbling  up  be  owing .' 

A.  It  would  be  owing  to  the  escape  of  carbonic  acid 
from  the  carbonate  of  lime  which  the  soil  or  marl  conr 
tained. 

Here  the  teacher  may  perform  this  experiment  by  pour- 
ing weak  acid  upon  marl  or  powilereil  chalk  in  a  wine 
glasSj  and  showing   the   bubbling   up.     He  may  further 


CHEMISTRY    AND    GEOLOGY. 


63 


convince  his  pupils  that   the  gas  given  off  is  really  car- 
bonic aciJ,  by    introducing  a  lighted  taper  into  the  glass 
when  it  will  be  extinguished.      (See  fig.  2.) 
Q.    fFhat  takes  place  when  limestone  {carbunate  of  lime) 
is  bamcd  in  the  kiln  ? 
A.  The  carbonic   acid  is   driven   ofl'  from  tlie  IIm&- 
slone  by  the  heat,  and  the  lime  alone  remains. 
Q.    jyhat  is  the  lime  called  iri  this  state  ? 

A.  It  is  called  burned  lime,  quick-lime,  caustic  lime, 
hot  lime,  lime  shells,  &c. 

Q.    What  weight  of  quick-lime  or  lime-shells  is  obtaintd 
from  a  ton  of  limestone  7 

A.  A  ton  of  limestone  yields  about  11 J  cwts.  of  quick- 
lime. 

Q.    fVhat  takes  place  when  water  is  poured  upon  quick- 
lime ? 
A.  The   quick-lime   drinks   in   the   water,    becomes 
very  liot.  shells  up,  and 
gradually  falls  to  pow- 
der. 

The  teacher  may  ex- 
hibit   this   effect   of 
water     upon     lime, 
and   may  satisfy  his 
pupils  that  the  heat 
produced  is  great,  by  showing  that  it  will  sometimes sel 
fire  to  gunpowder  placed  upon  a  dry  portion  of  the  lime, 
or  will  heat  a  cold,  baked  pie,  when   put   in  Ihe  middls 
of  it.     He  may  also  explain    to    them  that  it  is  the  heal 
thus  given  off  which  occasionally  sets  lire  to  the  sod  wiUt 


€4  C-1TECHT5JI   or   ACXKClTnAI. 

vkich  bea{is  of  Une-ifaidls  arc 

Q.   rr&^  is  tkia  ptmriag  ofw^er  «pM  iuK,  w  a  to 

A.  h  b  asoallj  called  siakn^  the  loBe.  aDid  ^Ome 
isealkd  daked  or  ^firfrrd  lime. 
Q.  J)aa  the  qmfHimf  iacraua  ni  ma^  miat  tf-'r~i  f 

A.  Tes:  eae  taa of  pne  qoickliaae  beeooKS  SSots, 
•TrfdxdliBe. 

f^ed  to  {&E  atr  ? 
A.  Tes,  it  xbeocfas  water  6«b  the  air,  aad  gndaDf 
hUs  to  powder. 

Q.  /)tes  ^ci£ae  Aiajkai(sfa0r&)cBjtta5'eiae,^raaa 
tiemrl 
A.  Tes,  it  griilaillT  driaks  ia  caiboEic  acid  frosfte 
Br,  and  recons  at  le^&  to  ike  stafe  of  nrfriitfr 

Tbe  teaeiur  b^   hoe  nP-''  i 

flhas  a&soc^  eacteaie  aca<  L.' . 
Helii  ■  ifi  I- iaeoa  tariil;- 
Bootible  filia  of    wkiee  c^ 

tarma  on  ks  iiiafii  i       T>'< 
teil  farcke  pocpose    : 
eaaboaTe  aeM  esiss 


apoa  qaiefcl  - 

^■i>!k>wf2j 

u  it  jiiTj-  - 
A.  Yes    ..  _-. 


CHEWIETBY    AMI    CEOLOCT.  M 

C4XiU  be  g<o(  bj  any  other  me»ni,  and  can  ibus  l/»  ^t.'jt* 
tboroa^il}'  mixtd  wUb  (b«  w/iJ. 

Q.    ffAot  i(  t/  unuUly  calUd  xeken  it  hat  thut  rditnui 
to  the  state  of  a  carUm-iite  1 

A.  ]l  u  uKuail/  called  mild  lime,  \a  dittiag^udi  it 
from  the  quick  or  cauctic  Ime. 

Q.  Doe$  qu.v:k-Umt   act   in   a   different   leey  upon   Hut 
land  JTvm  mild  km*  f 

A.  It  acu  very  luucb   ia  ti>e   lanie  way,   but  mora 
««ii<.kly. 
^  Houi  do  tKey  both  act  ? 

A.  Tbey  act  by  supplying:  (be  lin»e  »Li'.b  all  planto 
require  ai  part  of  ibeir  food, — by  cottibiiujug  «iil>  acid* 
in  ibe  toil,  xi  at  lo  remore  the  tourtkete  of  Ibc  UmJ, — 
aod  by  C4>0Terting  tbe  vegetable  tiiaUer  iulo  the  food  ol 
pUolf. 

Q.    Would  you  burn  lime  de^f,  or  vxnUd  you  kuf  -.1  ntar 
tht  tMrJact  1 

A-  I  would  alarayf  keep  it  oear  tbe  tmiiuot,  ae  it  bu 
k  natml  teodeticy  to  sink. 

Q.   TV  tehof  fon^  tocmU  yov  ofply  qtick-Hau  rallurr  iKam 
miUUmel 

A.  I  would  apply  qtack-fime  to  pealy  soils,  to  heai7 
day  Kiilt,  to  arable  laadf  wbich  are  very  Kour,  and  19 
Rjcb  »t  cODlaiii  a  ;^reat  deal  of  vegetable  matler. 
Q.    fVili  tke  aame  tjwmtity  of  limu  ff*4mcf  tin  aaaM  •* 
a  greater  effect  livon  dratrud  than  vftrri  v>tt  land  1 

A.  Tbe  nnte  <}tianlilT  will   prodoce  a  gT<«t*r  eflaci 
■poD  draawd  or  MtanBy  dry  fand,  tiMw  upon  wet  UnA 
5 


66  CATECHISM    OF   AGRICtTLTtJRAL 

Q.  Would  you  apply  lime  in  large  doses  at  long  inter- 
vals, or  in  small  doses  at  shorter  intervals  ? 
A.  11  I  applied  a  large  dose  of  lime  at  (lie  beginnings 
of  my  lease,  I  would  apply  smaller  doses  at  the  end  of 
each  rotation,  or  at  the  end  of  every  second  rotation,  to 
keep  up  the  quantity  of  lime  in  the  land. 

The  teacher  may  tiere  explain  the  meaning  of  the  ne\r 
word  rotation,  and  may  illu^itrate  it  by  reference  to  the 
course  of  cropping  in  his  own  or  neighboring  districts  ; 
and  if  he  make  himself  master  of  the  theory  of  rota- 
tions (see  the  Author's  Licturts  on  Agricultural  ChemiS' 
try  and  Geology,  page  717,)  he  may  give  his  pupils 
correct  notions  upon  this  subject,  which  they  will  seldom 
forget  in  after  life. 
Q.    Why  does  liiiie  require  to  be  repeated  ? 

A.  Cliicfly  for  three  reasons:  ^rs^,  because  the  crops 
cat  up  and  carry  off  a  portion  of  the  lime;  second,  be- 
cause a  poition  of  it  sinks  into  the  subsoil;  and  thirdly, 
because  the  rains  are  always  washing  a  portion  of  it  out 
of  the  land. 

VII.  —  OF     THE     COMPOSITION     OF    THE   CROPS 
WHICH    THE      FAR31ER    REAPS. 

Q,  Of  what  substances  do  the  difftrent  kinds  of  grain 

usually  consist  ? 
.  A.  They   consist   chiefly  of  three  substances,  starch, 
gluten,  and  oil  or  fat. 

Q.    IVhat  proportion  of  each  of  these  usually  exists  in 
wheat  7 
A.  103  lbs.  of  wheat  flour   contain  about  50  lbs.  of 
ctarch,  10  lbs.  of  gluten,  and  2  or  3  lbs.  of  oil. 


CHEMISTRY  AND  GEOLOGY.  67 

Q.  In  what  proportion  do  they  exist  in  oats  ? 

A.  100  lbs.  of  oats  contain  about  60  lbs.  of  starch,  18 
lbs.  of  gluten,  and  6  lbs.  of  oil. 
Q.    JVhat  do  potatoes  and  turnips  principally  consist  oft 

A.  Tlieir  principal  constituent  is  water. 
Q.  Hoii  muchioateris  contained  in  100  /6s.  of  potatoes'! 

A-  100  lbs.  of  potatoes,  contain  about  75  lbs.  of  wa- 
ter. 
Q.  ffow  much  water  is  contained  in  100  Ihs.  of  turnips  ? 

A.  100  lbs.  of  turnips  contain  about  88  lbs.  of  water. 
Q.    IVhat  quantity  of  starch  do  potatoes  contain  ? 

A.  100  lbs.  of  potatoes  contain  from  Ij  to  20  lbs.  of 
starch. 

Q.  jfre  the^e  proportions  of  starch,  gluten,  Sfc.  always 
the  same  in  the  same  grain  or  root  ? 

A.  No.  Some  varieties  of  wheat  contain  more  glu- 
ten than  others,  some  varieties  of  oats  more  oil  than  oth- 
ers, and  some  varieties  of  potatoes  more  starch  than 
others. 

Q.  Have  the  soil  and  climate  any  influence  upon  the 
proportions  of  these  ingredients  ? 

A.  Yes,  the  wheat  of  warm  climates  is  said  to  contain 
more  gluten,  and  the  potatoes  and   barley  grown  upon 
liglit  or  well  drained  land,  more  starch. 
Q.    When  grain  or  potatoes  are  burned,  do  they  leavi 
any  inorganic  matter  or  ash  ? 

A.  Yes,  they  all  leave  a  small  quantity  of  ash  when 
burned. 
Q.   Of  what  does  this  ash  consist  ? 

A.  It  consists  of  the  phosphates  of  potash,  soda,  lime 


63  CATECHISM   OF   AGEICULTURAL 

and  magnesia,  of  common  salt,  and  other  saline  sub- 
stances. 

The  teacher  may  here  explain  more  fully  the  composition 
of  this  ash,  by  referring  to  his  table,  (III.)  which  exhi 
bits  the  composition  of  the  ash  of  (lifTereiit  kinds  of  grain, 
anit  explaining  that  the  ash  both  of  corn  am!  of  the  ordi. 
nary  root  crops,  contains  a  certain  quantity  of  all  the 
substances  there  mentioned,  but  that  phosphoric  acid,  in 
combination  with  potash,  soda,  magnesia  and  lime  are 
its  Tnost  important  ingredients.* 

VIII. — USES  OP  THE    CROPS    IN    FEEDING. 

Q.    JVhat  natural  purposes   are   vegetables  intended  to 
serve! 
A.  They  are  chiefly  intended  for  the  food  of  animals. 
Q.    fVhat  substances  must  an   animal  derive  from   its 
food,  that  it  may  be  maintained  in  a  healthy  stale  ? 
A.  It  must  obtain  starch,  gluten,  oil  or  fat,  and  saline 
or  inorganic  matter. 
Q.  Do  you  recollect  what  starch  co/isists  of! 

A.  Starch  consists  of  carbon  and  water. 
Q.  Ihr  what  purpose  does  an  animal  require  starch  in 
itsjood  ! 
A.  It  requires  starch  to  supply  the  carbon  which  it 
throws  off  from  its  lungs  during  respiration. 

The  teacher  may  here  explain  that  gum  and  sugar,  which 

*  It  will  be  perceived  that  there  is  inserted  no  account  of  the  composition 
of  Indian  com  ;  this  is  because  there  has  been  as  yet,  no  complete  anajyss 
of  it.  It  is  my  intention,  in  Prof,  Johnston's  Laboratory,  and  under  his  di- 
rection, soon  to  commence  an  extended  examination  of  tliia  grain,  .so  im- 
portant to  our  country.— J.  P.  Nobtom. 


CHEMISTEY    AND    GEOLOGY.  69 

«l»o  consist  of  carbon  anj  water  only,  (p.  27,)  serve  Iha 
same  purpose  when  eaten  as  (he  starch  of  our  food  (loe«, 
and  that  wliat  is  here  said  for  simplicity  of  starch  only, 
is  true  also  of  the  sugar  and  gum  contained  in  the  vege- 
table substances  we  eat. 
Q.  Do  you  recollect  how  much  carbon  a  man  throws  off 
from  his  lungs  in  a  day  ? 
A.  Yes,  he  throws  off  from  six  to  eight  ounces  in  a 
day. 

Q.    fVhat  quantity  of  starch  must  he  eat,  in  order  to 
supply  the  quantity  of  carbon  given  off  from  his 
lungs  in  a  day  ? 
A.  He  will  require  to  eat  nearly  a  pound  of  starch  in 
a  day. 

10  oz.  of  starch  contain  about  4^  of  carbon,  (p.  27.) 
Q.  In  what  form  is  the  carbon  given  off  from  the  lungs 
of  animals  ? 
A.  It  is  given  off  in  the  form  of  carbonic  acid  gas. 
Q.    iVhat  becomes  of  the  carbonic  acid  gas  thus  given  offt 
A.  It  is  diffused  through  the  air,  and  afterwards  ab- 
sorbed again  by  plants,  in  order  that  new  quantities  of 
starch  may  be  produced  from  it. 

The  teacher  may  here  appropriately  draw  the  especial  at- 
tention of  his  pnpils  to  the  beautiful  cycle  of  natural  ope- 
rations here  described.  Even  children  may  be  made  to 
see  the  beauty  and  bounty  of  the  processes  by  which  the 
same  carbon  is  again  and  again  transformed  by  the  plant 
into  starch,  and  by  the  animal  into  carbonic  acid — as  well 
as  the  purpose  for  which  these  changes  are  made  to  take 
place — namely,  (o  keep  up  the  warmth  of  the  animal 
body. 


70  CATECHISM    OF    AGHICTTLTUBAL 

Q.  Fbr  what  purpose  does  an  animal  require  glutm,  in 
its  food  ? 

A.  An  animal  requires  gluten  for  the  pnrpose  of  re- 
pairing the  daily  waste  of  the  muscles  or  lean  part  of 
its  body. 
Q.  Are  the  muscles  of  an  animal  really  subject  to  waste  ? 

A.  Yes,  nearly  all  the  parts  of  the  body  suffer  a  cer- 
tain waste  every  day. 
Q.    JVhat  becomes  of  the  part  that  thus  wastes  away  7 

A.  It  is  carried  through  the  body,  and  forms  part  of 
(he  dung  and  urine  of  the  animal. 

Q.  IJow  can  the  gluten  repair  the  waste  of  the  musclet 
or  lean  part  of  the  animal? 

A.  Because  the  gluten  of  plants  is  exactly  the  same 
thing  as  the  muscles  of  animals. 
Q.    Why  does  the  animal  require  oil  or  fat  in  its  food  ? 

A.  To  supply  the  natural  waste  of  fatty  matter  which 
takes  place. 
Q.  Does  it  serve  any  other  purpose  ? 

A.  Yes,  when  more  is  given  than  is  necessary  to  sup 
ply  the  waste  it  may  make  the  animal  fat. 
Q.  Is  food  that  contains  much  oil,  then,  the  best  for  fat 
tening  ? 

A.  Yes,  of  two  samples  of  food  that  which  contains 
the  most  oil  will  fatten  most  quickly. 
Q.  Is  this  one  reason  why  oil-cake  is   so  good  for  fat- 
tening stock  ? 

A.  Yes,  it  is  one  reason. 
Q.    Jlliy  must  the  food  of  animals  contain  phosphate  of 
lime  and  other  inorganic  matter  7 


CHEMISTRY    AND    GEOLOGT.  71 

A.  To  supply  the    daily   waste   of    the  bones,  of  the 
,  ilts  in  Ihe  blood,  &c. 

Q.  Do  not  the  gluten  and  the  saline  mutter  serve  a  fur- 
ther purpose  when  the  animal  is  growing  ? 
A.  Yes,  when  the  animal  is  gfrowing;  they  not  only  sup- 
ply the  daily  waste,  but  are  daily  adding  to  the  weight 
of  the  animal's  body. 

Q.    TVill  a  growing   atiimal  on  this  account  reqv.ire  a 
larger  supply  of  these  kinds  of  food  ? 
A.  Yes,  a  growing   animal  of  the  same  size  will  re- 
quire more  of  these  kinds  of  food  than  a  full-grown  ani- 
mal. 

Q.   Suppose  an  equal  quantity  of  food  given  to  a  grow- 
ing and  to  a  full-grown  animal,  which  of  them  mil 
give  the  richer  dung  ? 
A.  The  full-grown  animal  will  give  the  richer  dung. 
Q.    Why  so  ? 

A.  Because  the  growing  animal  extracts  and  retains 
more  of  the  substance  of  the  food. 
Q.    Why  does  it  do  this  .' 

A.  Because  it  has  both  to  supply  the  natural  waste  of 
its  own  body,  and  to  add  to  its  size,  wliile  the  full-grown 
animal  has  only  to  supply  the  waste. 
Q.  Why  is  the  dung  (f  fattening  slock  richer  than  that 
of  growing  stock  ? 
A.  Because  fattening  stock  extract  and  retain  only 
the  oil  and  starch  of  their  food,  and  reject  the  remain- 
der. 

Q.  I/ow  would  you  convert  a  ton  of  oats  or  turnips  into 
the  largest  quantity  of  beef  or  mutton  ? 


72  CATECHISM    OF    AGRICULTURAL 

A.  I  would  keep  my  callle  or  sheep  in  a  warmer 
sheltered  place, — where  they  might  have  wholesome  air, 
and  but  little  light. 

Q.  If  you  wanted  merely  to  fatten  a  fullgrown  beast, 
what  would  you  do  ? 
A.  I  would  keep  it  warm,   disturb  it  little,  and  give 
it  oil-cake  or  oats,  with  a  good  supply  of  turnips. 

The  degree  of  warmth  ami  confinement  under  which  ani- 
mals will  thrive  ilepenils   much    upon    the  breed.     The 
hardy  and  wild  West  Highlander  would  pineavay  in  the 
warm  and  confined  sheds   in    which    the    Teeswaler  ox 
thrives  best, — and  Ihe  black-faced  sheep  would  lose  flesh 
and   become  unheallhy    where    the   delicate   Leicester 
would  thrive  and  fallen. 
Q.  If  you  wished  only  to  convert  a  large   quantity  of 
hay,    straw,   or  turnips  into   manure,  what  would 
you  do  ? 
A.  I  would  put  my  stock  into  a  cool  and  less  sheltered 
place,  and  1  would  make  Ihem  take  a  good  deal  of  ex- 
ercise; 

Q.  If  you  roished  to  make  a  cow  give  you  the  largest 
possible  quantity  of  milk,  how  would  you  f'.ed  herl 
A.  I  would  give  her  rich  juicy  grass,  turnips,  brew- 
er's grains,  mashes,  or  other  food  containing  much  wa- 
ter,— and  I  would  supply  her  with  drink  when  she  would 
take  it. 

Q.  But  to  obtain  mi'.k  of  the  best  possible  quality,  would 
you  do  so  ? 
A.  No.     I  would  then   give  her  as  much  dry  food, — 
oats,  beans,  bran  and  clover  hay, — as  she  would  eat 


CHEMISTRY    AND    GEOLOGY.  73 

Q.  If  you   rvanted  milk    particularly   rich   in   butter, 
what  would  you  give  ? 
A.  I  would  give  ber  the  same  kind  of  food  as  I  would 
to   a   fattening  animal, — oil-cake,   oats,  bailey,  Indian 
corn  meal,  and  some  turnips. 

Q.  Hut  if  you  were  going  to  make  cheese  of  your  milk, 
would  you  give  the  same  kind  of  food  J 
A.  I  would  then  prefer  beans,  peas,  vetches,  and  clo- 
ver, or  clover  hay,  all  of  which  make  the  milk  richer  in 
curd. 

Q.  j/s  a  general  rule  in  fattening  off  milk  cows  or  pigs, 
would  you  give  the  food  siveet  or  sour  J 
A.  To  pigs  I  would  give  it  slightly  sour,  to  fattening 
cows  and  bullocks  I  would  give  it  fresh  and  sweet. 

In  some  of  the  great  London  dairies — as  that  of  the  Messrs. 
LaycDcU  at  Islington — the  brewers'  grains  are  trodden 
while  hot  into  deep  pits  lined  with  brick,  and  covered 
over  with  a  layer  of  earth  so  as  to  exclude  the  air.  Treat- 
ed in  this  way,  they  are  said  to  become  more  saccharine 
and  nutritive,  anil  are  considered  none  the  worse  for  be- 
ing several  years  old. 

Q.    fVhy  would  you  give  it  sour  to  pigs  ? 

A.  Because  it  has  been  found  that  much  more  pork  is 
obtained  from  green  vegetables,  or  from  bean  meal  or 
boiled  potatoes,  when  mixed  with  water  and  left  to  sour, 
than  when  given  fresh  and  sweet. 

Q.  Is  there  any  thing  else  you  would  do  to  make  your 
stockfeeding  more  profitable  1 


74  CATECHISM    OF    AGRICULTURAL 

A.  Yes,  I  would  keep  my  cow  houses  well  ventilated, 
but  warm,  and  my  sheep  and  pigs  clean;  and  I  would 
feed  them  at  regular  intervalsj  and  at  least  three  times  a 
day. 


While  on  this  part  of  the  subject,  the  teacher  may  draw 
the  attention  of  his  pupils  to  the  beautiful  chemical  coa- 
necliun  which  exists  between  the  vegetable  and  animal 
kingiloms,  anil  especially  to  the  marked  adaptation  of 
the  living  vegetable  to  the  wants  of  the  living  anima], 
which  is  exhibited  in  the  fact,  that  the  animal  finils  ready 
formed  in  the  ripened  plant,  all  the  most  important  sub- 
stances of  which  its  own  body  iscomposeil.  The  gluten 
is  identical  wiih  the  fibre  of  its  muscles,  the  oil  similar 
in  character  with  the  fat  of  its  body,  while  the  bone 
earth  of  the  plant  supplies  materials  for  the  bones  of  the 
animal,  and  the  starch  and  sugar  atford  the  carbon  which 
is  necessary  for  the  purposes  of  respiration.  Finally,  he 
may  also  point  oul,  that,  when  the  vegetable  fooii  has 
discharged  its  office  in  the  animal  boily,  it  returns  to  the 
earth  in  the  form  of  dung — only  to  enter  into  the  roots 
of  new  plants,  and  thus  to  produce  new  supplies  of  sus- 
tenance fur  oiher  races  of  animals.  The  en'ire  economy 
of  vegetable  and  animal  life,  and  all  the  changes  expe- 
rienceil  by  dead  matter,  are  parts  of  one  system — ex- 
press, as  it  were,  but  one  idea,  the  offspring  of  ONX 
MIND. 


STSBEOTTrSD   AND   FRinT£D    BT    C.    TAJ1   BENTHUTSEH 


14  DAY  USE 

RETURlrf'CftJ^^KLFRy  Si  "wlii(aR*CJIURO  WED 

^O    (JiAi^il^ill^il     HALL 
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ALBANY.         1 


Merchants  aua  Teachers  supplied  l>vith  SCHO'ti. 
BOOKS,  at  wholesale,  al  the  lowest  prices. 

AOENCY    FOR  ' 

mitchell'S  Outli}\e  Hapt, 

Reccmly  revised  and  impi5Qve<i  witu  a  lar,s:c  additional 
Map  ol    Europe,  liighly  coloml,  with  key 


Particular 
furnishing    Public,   Pmtate,  and 


attention   given    In 
School  Libbai.iks. 

Holbrook's  Scientific  Appararus  for  Schools. 
Globes, 

10,  12  and  13  inch,  in  paiis  or  separate:    AUo5  inc)i 
Globes,  a  good  article  at  a  low  price. 

ISedical,  Classical,  Scientific  and  Standard 

Works. 

Agricultural  Books. 

Stationery, 

AT   WHOLESALE  AND   KETAIl.. 

A  general assortmentofBKAKK  ACCOUNT  BOOKS 
always  on  hand,  or  made  to  orde    on  short  noti  ;e. 

ACENCV    y'OR 

Levi  Brown's  Diamond  Foiated  Gold  Fens. 

\lso.  as  above,  a  gensrai  Sabbati.  .jchool  Dt  pcsitt  ef 
:A  Theological  Book  SHorc 

, -m 


